Revert everything related to csharp client to reduce the size of the change

Removing the x-is-value-type which was a buggy and old version of the new x-csharp-value-type that work for every type.

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java

@@ -575,8 +575,10 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
             property.isPrimitiveType = true;
         }
 
+        property.isNullable = true;
         if (!property.isContainer && (nullableType.contains(property.dataType) || property.isEnum)) {
             property.vendorExtensions.put("x-csharp-value-type", true);
+            property.isNullable = false;
         }
 
         property.vendorExtensions.put("x-is-value-type", isValueType(property));
@@ -867,6 +869,7 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
                 }
             }
 
+            parameter.isNullable = true;
             if (model != null) {
                 // Effectively mark enum models as enums and non-nullable
                 if (model.isEnum) {
@@ -874,11 +877,13 @@ public abstract class AbstractCSharpCodegen extends DefaultCodegen implements Co
                     parameter.allowableValues = model.allowableValues;
                     parameter.isPrimitiveType = true;
                     parameter.vendorExtensions.put("x-csharp-value-type", true);
+                    parameter.isNullable = false;
                 }
             }
 
             if (!parameter.isContainer && nullableType.contains(parameter.dataType)) {
                 parameter.vendorExtensions.put("x-csharp-value-type", true);
+                parameter.isNullable = false;
             }
 
             if (!parameter.required && parameter.vendorExtensions.get("x-csharp-value-type") != null) { //optional

modules/openapi-generator/src/main/resources/aspnetcore/2.1/model.mustache

@@ -104,14 +104,14 @@ namespace {{modelPackage}}
             return {{#vars}}{{^isContainer}}
                 (
                     {{name}} == other.{{name}} ||
-                    {{^vendorExtensions.x-is-value-type}}{{name}} != null &&{{/vendorExtensions.x-is-value-type}}
+                    {{#isNullable}}{{name}} != null &&{{/isNullable}}
                     {{name}}.Equals(other.{{name}})
                 ){{^-last}} && {{/-last}}{{/isContainer}}{{#isContainer}}
                 (
                     {{name}} == other.{{name}} ||
-                    {{^vendorExtensions.x-is-value-type}}{{name}} != null &&
+                    {{#isNullable}}{{name}} != null &&
                     other.{{name}} != null &&
-                    {{/vendorExtensions.x-is-value-type}}{{name}}.SequenceEqual(other.{{name}})
+                    {{/isNullable}}{{name}}.SequenceEqual(other.{{name}})
                 ){{^-last}} && {{/-last}}{{/isContainer}}{{/vars}}{{^vars}}false{{/vars}};
         }
 
@@ -126,7 +126,7 @@ namespace {{modelPackage}}
                 var hashCode = 41;
                 // Suitable nullity checks etc, of course :)
                 {{#vars}}
-                    {{^vendorExtensions.x-is-value-type}}if ({{name}} != null){{/vendorExtensions.x-is-value-type}}
+                    {{#isNullable}}if ({{name}} != null){{/isNullable}}
                     hashCode = hashCode * 59 + {{name}}.GetHashCode();
                 {{/vars}}
                 return hashCode;

modules/openapi-generator/src/main/resources/aspnetcore/3.0/model.mustache

@@ -72,7 +72,7 @@ namespace {{modelPackage}}
         [MinLength({{minLength}})]{{/maxLength}}{{/minLength}}{{^minLength}}{{#maxLength}}
         [MaxLength({{.}})]{{/maxLength}}{{/minLength}}{{#minimum}}{{#maximum}}
         [Range({{minimum}}, {{maximum}})]{{/maximum}}{{/minimum}}
-        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#isNullable}}true{{/isNullable}}{{^isNullable}}{{#vendorExtensions.x-is-value-type}}true{{/vendorExtensions.x-is-value-type}}{{^vendorExtensions.x-is-value-type}}false{{/vendorExtensions.x-is-value-type}}{{/isNullable}})]
+        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#isNullable}}true{{/isNullable}}{{^isNullable}}{{#vendorExtensions.x-csharp-value-type}}true{{/vendorExtensions.x-csharp-value-type}}{{^vendorExtensions.x-csharp-value-type}}false{{/vendorExtensions.x-csharp-value-type}}{{/isNullable}})]
         {{#isEnum}}
         public {{{datatypeWithEnum}}}{{#isNullable}}?{{/isNullable}} {{name}} { get; set; }{{#defaultValue}} = {{{.}}};{{/defaultValue}}
         {{/isEnum}}
@@ -144,14 +144,14 @@ namespace {{modelPackage}}
             return {{#vars}}{{^isContainer}}
                 (
                     {{name}} == other.{{name}} ||
-                    {{^vendorExtensions.x-is-value-type}}{{name}} != null &&{{/vendorExtensions.x-is-value-type}}
+                    {{#isNullable}}{{name}} != null &&{{/isNullable}}
                     {{name}}.Equals(other.{{name}})
                 ){{^-last}} && {{/-last}}{{/isContainer}}{{#isContainer}}
                 (
                     {{name}} == other.{{name}} ||
-                    {{^vendorExtensions.x-is-value-type}}{{name}} != null &&
+                    {{#isNullable}}{{name}} != null &&
                     other.{{name}} != null &&
-                    {{/vendorExtensions.x-is-value-type}}{{name}}.SequenceEqual(other.{{name}})
+                    {{/isNullable}}{{name}}.SequenceEqual(other.{{name}})
                 ){{^-last}} && {{/-last}}{{/isContainer}}{{/vars}}{{^vars}}false{{/vars}};
         }
 
@@ -166,7 +166,7 @@ namespace {{modelPackage}}
                 var hashCode = 41;
                 // Suitable nullity checks etc, of course :)
                 {{#vars}}
-                    {{^vendorExtensions.x-is-value-type}}if ({{name}} != null){{/vendorExtensions.x-is-value-type}}
+                    {{#isNullable}}if ({{name}} != null){{/isNullable}}
                     hashCode = hashCode * 59 + {{name}}.GetHashCode();
                 {{/vars}}
                 return hashCode;

samples/client/others/csharp-netcore-complex-files/src/Org.OpenAPITools/Model/MultipartArrayRequest.cs

@@ -45,7 +45,7 @@ namespace Org.OpenAPITools.Model
         /// Many files
         /// </summary>
         /// <value>Many files</value>
-        [DataMember(Name = "files", EmitDefaultValue = false)]
+        [DataMember(Name = "files", EmitDefaultValue = true)]
         public List<System.IO.Stream> Files { get; set; }
 
         /// <summary>

samples/client/others/csharp-netcore-complex-files/src/Org.OpenAPITools/Model/MultipartMixedRequest.cs

@@ -66,7 +66,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Marker
         /// </summary>
-        [DataMember(Name = "marker", EmitDefaultValue = false)]
+        [DataMember(Name = "marker", EmitDefaultValue = true)]
         public MultipartMixedRequestMarker Marker { get; set; }
 
         /// <summary>
@@ -79,7 +79,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets StatusArray
         /// </summary>
-        [DataMember(Name = "statusArray", EmitDefaultValue = false)]
+        [DataMember(Name = "statusArray", EmitDefaultValue = true)]
         public List<MultipartMixedStatus> StatusArray { get; set; }
 
         /// <summary>

samples/client/others/csharp-netcore-complex-files/src/Org.OpenAPITools/Model/MultipartMixedRequestMarker.cs

@@ -44,7 +44,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
-        [DataMember(Name = "name", EmitDefaultValue = false)]
+        [DataMember(Name = "name", EmitDefaultValue = true)]
         public string Name { get; set; }
 
         /// <summary>

samples/client/others/csharp-netcore-complex-files/src/Org.OpenAPITools/Model/MultipartSingleRequest.cs

@@ -45,7 +45,7 @@ namespace Org.OpenAPITools.Model
         /// One file
         /// </summary>
         /// <value>One file</value>
-        [DataMember(Name = "file", EmitDefaultValue = false)]
+        [DataMember(Name = "file", EmitDefaultValue = true)]
         public System.IO.Stream File { get; set; }
 
         /// <summary>

samples/client/petstore/csharp-netcore-functions/src/Org.OpenAPITools/Models/ApiResponse.cs

@@ -35,13 +35,13 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Type
         /// </summary>
-        [DataMember(Name="type", EmitDefaultValue=false)]
+        [DataMember(Name="type", EmitDefaultValue=true)]
         public string Type { get; set; }
 
         /// <summary>
         /// Gets or Sets Message
         /// </summary>
-        [DataMember(Name="message", EmitDefaultValue=false)]
+        [DataMember(Name="message", EmitDefaultValue=true)]
         public string Message { get; set; }
 
         /// <summary>

samples/client/petstore/csharp-netcore-functions/src/Org.OpenAPITools/Models/Category.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Models
         /// Gets or Sets Name
         /// </summary>
         [RegularExpression("^[a-zA-Z0-9]+[a-zA-Z0-9\\.\\-_]*[a-zA-Z0-9]+$")]
-        [DataMember(Name="name", EmitDefaultValue=false)]
+        [DataMember(Name="name", EmitDefaultValue=true)]
         public string Name { get; set; }
 
         /// <summary>

samples/client/petstore/csharp-netcore-functions/src/Org.OpenAPITools/Models/Pet.cs

@@ -35,27 +35,27 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Category
         /// </summary>
-        [DataMember(Name="category", EmitDefaultValue=false)]
+        [DataMember(Name="category", EmitDefaultValue=true)]
         public Category Category { get; set; }
 
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
         [Required]
-        [DataMember(Name="name", EmitDefaultValue=false)]
+        [DataMember(Name="name", EmitDefaultValue=true)]
         public string Name { get; set; }
 
         /// <summary>
         /// Gets or Sets PhotoUrls
         /// </summary>
         [Required]
-        [DataMember(Name="photoUrls", EmitDefaultValue=false)]
+        [DataMember(Name="photoUrls", EmitDefaultValue=true)]
         public List<string> PhotoUrls { get; set; }
 
         /// <summary>
         /// Gets or Sets Tags
         /// </summary>
-        [DataMember(Name="tags", EmitDefaultValue=false)]
+        [DataMember(Name="tags", EmitDefaultValue=true)]
         public List<Tag> Tags { get; set; }
 
 

samples/client/petstore/csharp-netcore-functions/src/Org.OpenAPITools/Models/Tag.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
-        [DataMember(Name="name", EmitDefaultValue=false)]
+        [DataMember(Name="name", EmitDefaultValue=true)]
         public string Name { get; set; }
 
         /// <summary>

samples/client/petstore/csharp-netcore-functions/src/Org.OpenAPITools/Models/User.cs

@@ -35,37 +35,37 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Username
         /// </summary>
-        [DataMember(Name="username", EmitDefaultValue=false)]
+        [DataMember(Name="username", EmitDefaultValue=true)]
         public string Username { get; set; }
 
         /// <summary>
         /// Gets or Sets FirstName
         /// </summary>
-        [DataMember(Name="firstName", EmitDefaultValue=false)]
+        [DataMember(Name="firstName", EmitDefaultValue=true)]
         public string FirstName { get; set; }
 
         /// <summary>
         /// Gets or Sets LastName
         /// </summary>
-        [DataMember(Name="lastName", EmitDefaultValue=false)]
+        [DataMember(Name="lastName", EmitDefaultValue=true)]
         public string LastName { get; set; }
 
         /// <summary>
         /// Gets or Sets Email
         /// </summary>
-        [DataMember(Name="email", EmitDefaultValue=false)]
+        [DataMember(Name="email", EmitDefaultValue=true)]
         public string Email { get; set; }
 
         /// <summary>
         /// Gets or Sets Password
         /// </summary>
-        [DataMember(Name="password", EmitDefaultValue=false)]
+        [DataMember(Name="password", EmitDefaultValue=true)]
         public string Password { get; set; }
 
         /// <summary>
         /// Gets or Sets Phone
         /// </summary>
-        [DataMember(Name="phone", EmitDefaultValue=false)]
+        [DataMember(Name="phone", EmitDefaultValue=true)]
         public string Phone { get; set; }
 
         /// <summary>

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Activity.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ActivityOutputs
         /// </summary>
-        [DataMember(Name = "activity_outputs", EmitDefaultValue = false)]
+        [DataMember(Name = "activity_outputs", EmitDefaultValue = true)]
         public Dictionary<string, List<ActivityOutputElementRepresentation>> ActivityOutputs
         {
             get{ return _ActivityOutputs;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ActivityOutputElementRepresentation.cs

@@ -55,7 +55,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Prop1
         /// </summary>
-        [DataMember(Name = "prop1", EmitDefaultValue = false)]
+        [DataMember(Name = "prop1", EmitDefaultValue = true)]
         public string Prop1
         {
             get{ return _Prop1;}
@@ -79,7 +79,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Prop2
         /// </summary>
-        [DataMember(Name = "prop2", EmitDefaultValue = false)]
+        [DataMember(Name = "prop2", EmitDefaultValue = true)]
         public Object Prop2
         {
             get{ return _Prop2;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/AdditionalPropertiesClass.cs

@@ -91,7 +91,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MapProperty
         /// </summary>
-        [DataMember(Name = "map_property", EmitDefaultValue = false)]
+        [DataMember(Name = "map_property", EmitDefaultValue = true)]
         public Dictionary<string, string> MapProperty
         {
             get{ return _MapProperty;}
@@ -115,7 +115,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MapOfMapProperty
         /// </summary>
-        [DataMember(Name = "map_of_map_property", EmitDefaultValue = false)]
+        [DataMember(Name = "map_of_map_property", EmitDefaultValue = true)]
         public Dictionary<string, Dictionary<string, string>> MapOfMapProperty
         {
             get{ return _MapOfMapProperty;}
@@ -163,7 +163,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MapWithUndeclaredPropertiesAnytype1
         /// </summary>
-        [DataMember(Name = "map_with_undeclared_properties_anytype_1", EmitDefaultValue = false)]
+        [DataMember(Name = "map_with_undeclared_properties_anytype_1", EmitDefaultValue = true)]
         public Object MapWithUndeclaredPropertiesAnytype1
         {
             get{ return _MapWithUndeclaredPropertiesAnytype1;}
@@ -187,7 +187,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MapWithUndeclaredPropertiesAnytype2
         /// </summary>
-        [DataMember(Name = "map_with_undeclared_properties_anytype_2", EmitDefaultValue = false)]
+        [DataMember(Name = "map_with_undeclared_properties_anytype_2", EmitDefaultValue = true)]
         public Object MapWithUndeclaredPropertiesAnytype2
         {
             get{ return _MapWithUndeclaredPropertiesAnytype2;}
@@ -211,7 +211,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MapWithUndeclaredPropertiesAnytype3
         /// </summary>
-        [DataMember(Name = "map_with_undeclared_properties_anytype_3", EmitDefaultValue = false)]
+        [DataMember(Name = "map_with_undeclared_properties_anytype_3", EmitDefaultValue = true)]
         public Dictionary<string, Object> MapWithUndeclaredPropertiesAnytype3
         {
             get{ return _MapWithUndeclaredPropertiesAnytype3;}
@@ -236,7 +236,7 @@ namespace Org.OpenAPITools.Model
         /// an object with no declared properties and no undeclared properties, hence it&#39;s an empty map.
         /// </summary>
         /// <value>an object with no declared properties and no undeclared properties, hence it&#39;s an empty map.</value>
-        [DataMember(Name = "empty_map", EmitDefaultValue = false)]
+        [DataMember(Name = "empty_map", EmitDefaultValue = true)]
         public Object EmptyMap
         {
             get{ return _EmptyMap;}
@@ -260,7 +260,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MapWithUndeclaredPropertiesString
         /// </summary>
-        [DataMember(Name = "map_with_undeclared_properties_string", EmitDefaultValue = false)]
+        [DataMember(Name = "map_with_undeclared_properties_string", EmitDefaultValue = true)]
         public Dictionary<string, string> MapWithUndeclaredPropertiesString
         {
             get{ return _MapWithUndeclaredPropertiesString;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Animal.cs

@@ -87,7 +87,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Color
         /// </summary>
-        [DataMember(Name = "color", EmitDefaultValue = false)]
+        [DataMember(Name = "color", EmitDefaultValue = true)]
         public string Color
         {
             get{ return _Color;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ApiResponse.cs

@@ -85,7 +85,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Type
         /// </summary>
-        [DataMember(Name = "type", EmitDefaultValue = false)]
+        [DataMember(Name = "type", EmitDefaultValue = true)]
         public string Type
         {
             get{ return _Type;}
@@ -109,7 +109,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Message
         /// </summary>
-        [DataMember(Name = "message", EmitDefaultValue = false)]
+        [DataMember(Name = "message", EmitDefaultValue = true)]
         public string Message
         {
             get{ return _Message;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Apple.cs

@@ -55,7 +55,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Cultivar
         /// </summary>
-        [DataMember(Name = "cultivar", EmitDefaultValue = false)]
+        [DataMember(Name = "cultivar", EmitDefaultValue = true)]
         public string Cultivar
         {
             get{ return _Cultivar;}
@@ -79,7 +79,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Origin
         /// </summary>
-        [DataMember(Name = "origin", EmitDefaultValue = false)]
+        [DataMember(Name = "origin", EmitDefaultValue = true)]
         public string Origin
         {
             get{ return _Origin;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ArrayOfArrayOfNumberOnly.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ArrayArrayNumber
         /// </summary>
-        [DataMember(Name = "ArrayArrayNumber", EmitDefaultValue = false)]
+        [DataMember(Name = "ArrayArrayNumber", EmitDefaultValue = true)]
         public List<List<decimal>> ArrayArrayNumber
         {
             get{ return _ArrayArrayNumber;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ArrayOfNumberOnly.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ArrayNumber
         /// </summary>
-        [DataMember(Name = "ArrayNumber", EmitDefaultValue = false)]
+        [DataMember(Name = "ArrayNumber", EmitDefaultValue = true)]
         public List<decimal> ArrayNumber
         {
             get{ return _ArrayNumber;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ArrayTest.cs

@@ -61,7 +61,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ArrayOfString
         /// </summary>
-        [DataMember(Name = "array_of_string", EmitDefaultValue = false)]
+        [DataMember(Name = "array_of_string", EmitDefaultValue = true)]
         public List<string> ArrayOfString
         {
             get{ return _ArrayOfString;}
@@ -85,7 +85,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ArrayArrayOfInteger
         /// </summary>
-        [DataMember(Name = "array_array_of_integer", EmitDefaultValue = false)]
+        [DataMember(Name = "array_array_of_integer", EmitDefaultValue = true)]
         public List<List<long>> ArrayArrayOfInteger
         {
             get{ return _ArrayArrayOfInteger;}
@@ -109,7 +109,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ArrayArrayOfModel
         /// </summary>
-        [DataMember(Name = "array_array_of_model", EmitDefaultValue = false)]
+        [DataMember(Name = "array_array_of_model", EmitDefaultValue = true)]
         public List<List<ReadOnlyFirst>> ArrayArrayOfModel
         {
             get{ return _ArrayArrayOfModel;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Capitalization.cs

@@ -79,7 +79,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets SmallCamel
         /// </summary>
-        [DataMember(Name = "smallCamel", EmitDefaultValue = false)]
+        [DataMember(Name = "smallCamel", EmitDefaultValue = true)]
         public string SmallCamel
         {
             get{ return _SmallCamel;}
@@ -103,7 +103,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets CapitalCamel
         /// </summary>
-        [DataMember(Name = "CapitalCamel", EmitDefaultValue = false)]
+        [DataMember(Name = "CapitalCamel", EmitDefaultValue = true)]
         public string CapitalCamel
         {
             get{ return _CapitalCamel;}
@@ -127,7 +127,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets SmallSnake
         /// </summary>
-        [DataMember(Name = "small_Snake", EmitDefaultValue = false)]
+        [DataMember(Name = "small_Snake", EmitDefaultValue = true)]
         public string SmallSnake
         {
             get{ return _SmallSnake;}
@@ -151,7 +151,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets CapitalSnake
         /// </summary>
-        [DataMember(Name = "Capital_Snake", EmitDefaultValue = false)]
+        [DataMember(Name = "Capital_Snake", EmitDefaultValue = true)]
         public string CapitalSnake
         {
             get{ return _CapitalSnake;}
@@ -175,7 +175,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets SCAETHFlowPoints
         /// </summary>
-        [DataMember(Name = "SCA_ETH_Flow_Points", EmitDefaultValue = false)]
+        [DataMember(Name = "SCA_ETH_Flow_Points", EmitDefaultValue = true)]
         public string SCAETHFlowPoints
         {
             get{ return _SCAETHFlowPoints;}
@@ -200,7 +200,7 @@ namespace Org.OpenAPITools.Model
         /// Name of the pet 
         /// </summary>
         /// <value>Name of the pet </value>
-        [DataMember(Name = "ATT_NAME", EmitDefaultValue = false)]
+        [DataMember(Name = "ATT_NAME", EmitDefaultValue = true)]
         public string ATT_NAME
         {
             get{ return _ATT_NAME;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ChildCat.cs

@@ -91,7 +91,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
-        [DataMember(Name = "name", EmitDefaultValue = false)]
+        [DataMember(Name = "name", EmitDefaultValue = true)]
         public string Name
         {
             get{ return _Name;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ChildCatAllOf.cs

@@ -89,7 +89,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
-        [DataMember(Name = "name", EmitDefaultValue = false)]
+        [DataMember(Name = "name", EmitDefaultValue = true)]
         public string Name
         {
             get{ return _Name;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ClassModel.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets VarClass
         /// </summary>
-        [DataMember(Name = "_class", EmitDefaultValue = false)]
+        [DataMember(Name = "_class", EmitDefaultValue = true)]
         public string VarClass
         {
             get{ return _VarClass;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/DeprecatedObject.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
-        [DataMember(Name = "name", EmitDefaultValue = false)]
+        [DataMember(Name = "name", EmitDefaultValue = true)]
         public string Name
         {
             get{ return _Name;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Dog.cs

@@ -61,7 +61,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Breed
         /// </summary>
-        [DataMember(Name = "breed", EmitDefaultValue = false)]
+        [DataMember(Name = "breed", EmitDefaultValue = true)]
         public string Breed
         {
             get{ return _Breed;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/DogAllOf.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Breed
         /// </summary>
-        [DataMember(Name = "breed", EmitDefaultValue = false)]
+        [DataMember(Name = "breed", EmitDefaultValue = true)]
         public string Breed
         {
             get{ return _Breed;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Drawing.cs

@@ -66,7 +66,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MainShape
         /// </summary>
-        [DataMember(Name = "mainShape", EmitDefaultValue = false)]
+        [DataMember(Name = "mainShape", EmitDefaultValue = true)]
         public Shape MainShape
         {
             get{ return _MainShape;}
@@ -90,7 +90,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ShapeOrNull
         /// </summary>
-        [DataMember(Name = "shapeOrNull", EmitDefaultValue = false)]
+        [DataMember(Name = "shapeOrNull", EmitDefaultValue = true)]
         public ShapeOrNull ShapeOrNull
         {
             get{ return _ShapeOrNull;}
@@ -138,7 +138,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Shapes
         /// </summary>
-        [DataMember(Name = "shapes", EmitDefaultValue = false)]
+        [DataMember(Name = "shapes", EmitDefaultValue = true)]
         public List<Shape> Shapes
         {
             get{ return _Shapes;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/EnumArrays.cs

@@ -119,7 +119,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ArrayEnum
         /// </summary>
-        [DataMember(Name = "array_enum", EmitDefaultValue = false)]
+        [DataMember(Name = "array_enum", EmitDefaultValue = true)]
         public List<EnumArrays.ArrayEnumEnum> ArrayEnum
         {
             get{ return _ArrayEnum;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/EnumTest.cs

@@ -268,7 +268,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets OuterEnum
         /// </summary>
 
-        [DataMember(Name = "outerEnum", EmitDefaultValue = true)]
+        [DataMember(Name = "outerEnum", EmitDefaultValue = false)]
         public OuterEnum? OuterEnum
         {
             get{ return _OuterEnum;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/File.cs

@@ -50,7 +50,7 @@ namespace Org.OpenAPITools.Model
         /// Test capitalization
         /// </summary>
         /// <value>Test capitalization</value>
-        [DataMember(Name = "sourceURI", EmitDefaultValue = false)]
+        [DataMember(Name = "sourceURI", EmitDefaultValue = true)]
         public string SourceURI
         {
             get{ return _SourceURI;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/FileSchemaTestClass.cs

@@ -55,7 +55,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets File
         /// </summary>
-        [DataMember(Name = "file", EmitDefaultValue = false)]
+        [DataMember(Name = "file", EmitDefaultValue = true)]
         public File File
         {
             get{ return _File;}
@@ -79,7 +79,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Files
         /// </summary>
-        [DataMember(Name = "files", EmitDefaultValue = false)]
+        [DataMember(Name = "files", EmitDefaultValue = true)]
         public List<File> Files
         {
             get{ return _Files;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Foo.cs

@@ -44,7 +44,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Bar
         /// </summary>
-        [DataMember(Name = "bar", EmitDefaultValue = false)]
+        [DataMember(Name = "bar", EmitDefaultValue = true)]
         public string Bar
         {
             get{ return _Bar;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/FooGetDefaultResponse.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets VarString
         /// </summary>
-        [DataMember(Name = "string", EmitDefaultValue = false)]
+        [DataMember(Name = "string", EmitDefaultValue = true)]
         public Foo VarString
         {
             get{ return _VarString;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/FormatTest.cs

@@ -375,7 +375,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets VarString
         /// </summary>
-        [DataMember(Name = "string", EmitDefaultValue = false)]
+        [DataMember(Name = "string", EmitDefaultValue = true)]
         public string VarString
         {
             get{ return _VarString;}
@@ -423,7 +423,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Binary
         /// </summary>
-        [DataMember(Name = "binary", EmitDefaultValue = false)]
+        [DataMember(Name = "binary", EmitDefaultValue = true)]
         public System.IO.Stream Binary
         {
             get{ return _Binary;}
@@ -548,7 +548,7 @@ namespace Org.OpenAPITools.Model
         /// A string that is a 10 digit number. Can have leading zeros.
         /// </summary>
         /// <value>A string that is a 10 digit number. Can have leading zeros.</value>
-        [DataMember(Name = "pattern_with_digits", EmitDefaultValue = false)]
+        [DataMember(Name = "pattern_with_digits", EmitDefaultValue = true)]
         public string PatternWithDigits
         {
             get{ return _PatternWithDigits;}
@@ -573,7 +573,7 @@ namespace Org.OpenAPITools.Model
         /// A string starting with &#39;image_&#39; (case insensitive) and one to three digits following i.e. Image_01.
         /// </summary>
         /// <value>A string starting with &#39;image_&#39; (case insensitive) and one to three digits following i.e. Image_01.</value>
-        [DataMember(Name = "pattern_with_digits_and_delimiter", EmitDefaultValue = false)]
+        [DataMember(Name = "pattern_with_digits_and_delimiter", EmitDefaultValue = true)]
         public string PatternWithDigitsAndDelimiter
         {
             get{ return _PatternWithDigitsAndDelimiter;}
@@ -598,7 +598,7 @@ namespace Org.OpenAPITools.Model
         /// None
         /// </summary>
         /// <value>None</value>
-        [DataMember(Name = "pattern_with_backslash", EmitDefaultValue = false)]
+        [DataMember(Name = "pattern_with_backslash", EmitDefaultValue = true)]
         public string PatternWithBackslash
         {
             get{ return _PatternWithBackslash;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/HasOnlyReadOnly.cs

@@ -44,7 +44,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Bar
         /// </summary>
-        [DataMember(Name = "bar", EmitDefaultValue = false)]
+        [DataMember(Name = "bar", EmitDefaultValue = true)]
         public string Bar { get; private set; }
 
         /// <summary>
@@ -58,7 +58,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Foo
         /// </summary>
-        [DataMember(Name = "foo", EmitDefaultValue = false)]
+        [DataMember(Name = "foo", EmitDefaultValue = true)]
         public string Foo { get; private set; }
 
         /// <summary>

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/List.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets var123List
         /// </summary>
-        [DataMember(Name = "123-list", EmitDefaultValue = false)]
+        [DataMember(Name = "123-list", EmitDefaultValue = true)]
         public string var123List
         {
             get{ return _var123List;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/LiteralStringClass.cs

@@ -45,7 +45,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets EscapedLiteralString
         /// </summary>
-        [DataMember(Name = "escapedLiteralString", EmitDefaultValue = false)]
+        [DataMember(Name = "escapedLiteralString", EmitDefaultValue = true)]
         public string EscapedLiteralString
         {
             get{ return _EscapedLiteralString;}
@@ -69,7 +69,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets UnescapedLiteralString
         /// </summary>
-        [DataMember(Name = "unescapedLiteralString", EmitDefaultValue = false)]
+        [DataMember(Name = "unescapedLiteralString", EmitDefaultValue = true)]
         public string UnescapedLiteralString
         {
             get{ return _UnescapedLiteralString;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/MapTest.cs

@@ -86,7 +86,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MapMapOfString
         /// </summary>
-        [DataMember(Name = "map_map_of_string", EmitDefaultValue = false)]
+        [DataMember(Name = "map_map_of_string", EmitDefaultValue = true)]
         public Dictionary<string, Dictionary<string, string>> MapMapOfString
         {
             get{ return _MapMapOfString;}
@@ -110,7 +110,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MapOfEnumString
         /// </summary>
-        [DataMember(Name = "map_of_enum_string", EmitDefaultValue = false)]
+        [DataMember(Name = "map_of_enum_string", EmitDefaultValue = true)]
         public Dictionary<string, MapTest.InnerEnum> MapOfEnumString
         {
             get{ return _MapOfEnumString;}
@@ -134,7 +134,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets DirectMap
         /// </summary>
-        [DataMember(Name = "direct_map", EmitDefaultValue = false)]
+        [DataMember(Name = "direct_map", EmitDefaultValue = true)]
         public Dictionary<string, bool> DirectMap
         {
             get{ return _DirectMap;}
@@ -158,7 +158,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets IndirectMap
         /// </summary>
-        [DataMember(Name = "indirect_map", EmitDefaultValue = false)]
+        [DataMember(Name = "indirect_map", EmitDefaultValue = true)]
         public Dictionary<string, bool> IndirectMap
         {
             get{ return _IndirectMap;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/MixedPropertiesAndAdditionalPropertiesClass.cs

@@ -139,7 +139,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Map
         /// </summary>
-        [DataMember(Name = "map", EmitDefaultValue = false)]
+        [DataMember(Name = "map", EmitDefaultValue = true)]
         public Dictionary<string, Animal> Map
         {
             get{ return _Map;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Model200Response.cs

@@ -79,7 +79,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets VarClass
         /// </summary>
-        [DataMember(Name = "class", EmitDefaultValue = false)]
+        [DataMember(Name = "class", EmitDefaultValue = true)]
         public string VarClass
         {
             get{ return _VarClass;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ModelClient.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets varClient
         /// </summary>
-        [DataMember(Name = "client", EmitDefaultValue = false)]
+        [DataMember(Name = "client", EmitDefaultValue = true)]
         public string varClient
         {
             get{ return _varClient;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Name.cs

@@ -97,7 +97,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Property
         /// </summary>
-        [DataMember(Name = "property", EmitDefaultValue = false)]
+        [DataMember(Name = "property", EmitDefaultValue = true)]
         public string Property
         {
             get{ return _Property;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/NullableClass.cs

@@ -307,7 +307,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ArrayItemsNullable
         /// </summary>
-        [DataMember(Name = "array_items_nullable", EmitDefaultValue = false)]
+        [DataMember(Name = "array_items_nullable", EmitDefaultValue = true)]
         public List<Object> ArrayItemsNullable
         {
             get{ return _ArrayItemsNullable;}
@@ -379,7 +379,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets ObjectItemsNullable
         /// </summary>
-        [DataMember(Name = "object_items_nullable", EmitDefaultValue = false)]
+        [DataMember(Name = "object_items_nullable", EmitDefaultValue = true)]
         public Dictionary<string, Object> ObjectItemsNullable
         {
             get{ return _ObjectItemsNullable;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ObjectWithDeprecatedFields.cs

@@ -67,7 +67,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Uuid
         /// </summary>
-        [DataMember(Name = "uuid", EmitDefaultValue = false)]
+        [DataMember(Name = "uuid", EmitDefaultValue = true)]
         public string Uuid
         {
             get{ return _Uuid;}
@@ -116,7 +116,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets DeprecatedRef
         /// </summary>
-        [DataMember(Name = "deprecatedRef", EmitDefaultValue = false)]
+        [DataMember(Name = "deprecatedRef", EmitDefaultValue = true)]
         [Obsolete]
         public DeprecatedObject DeprecatedRef
         {
@@ -141,7 +141,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Bars
         /// </summary>
-        [DataMember(Name = "bars", EmitDefaultValue = false)]
+        [DataMember(Name = "bars", EmitDefaultValue = true)]
         [Obsolete]
         public List<string> Bars
         {

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/OuterComposite.cs

@@ -85,7 +85,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets MyString
         /// </summary>
-        [DataMember(Name = "my_string", EmitDefaultValue = false)]
+        [DataMember(Name = "my_string", EmitDefaultValue = true)]
         public string MyString
         {
             get{ return _MyString;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Pet.cs

@@ -166,7 +166,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Category
         /// </summary>
-        [DataMember(Name = "category", EmitDefaultValue = false)]
+        [DataMember(Name = "category", EmitDefaultValue = true)]
         public Category Category
         {
             get{ return _Category;}
@@ -239,7 +239,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Tags
         /// </summary>
-        [DataMember(Name = "tags", EmitDefaultValue = false)]
+        [DataMember(Name = "tags", EmitDefaultValue = true)]
         public List<Tag> Tags
         {
             get{ return _Tags;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/ReadOnlyFirst.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Bar
         /// </summary>
-        [DataMember(Name = "bar", EmitDefaultValue = false)]
+        [DataMember(Name = "bar", EmitDefaultValue = true)]
         public string Bar { get; private set; }
 
         /// <summary>
@@ -63,7 +63,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Baz
         /// </summary>
-        [DataMember(Name = "baz", EmitDefaultValue = false)]
+        [DataMember(Name = "baz", EmitDefaultValue = true)]
         public string Baz
         {
             get{ return _Baz;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/SpecialModelName.cs

@@ -79,7 +79,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets VarSpecialModelName
         /// </summary>
-        [DataMember(Name = "_special_model.name_", EmitDefaultValue = false)]
+        [DataMember(Name = "_special_model.name_", EmitDefaultValue = true)]
         public string VarSpecialModelName
         {
             get{ return _VarSpecialModelName;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/Tag.cs

@@ -79,7 +79,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
-        [DataMember(Name = "name", EmitDefaultValue = false)]
+        [DataMember(Name = "name", EmitDefaultValue = true)]
         public string Name
         {
             get{ return _Name;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/TestCollectionEndingWithWordList.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Value
         /// </summary>
-        [DataMember(Name = "value", EmitDefaultValue = false)]
+        [DataMember(Name = "value", EmitDefaultValue = true)]
         public string Value
         {
             get{ return _Value;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/TestCollectionEndingWithWordListObject.cs

@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets TestCollectionEndingWithWordList
         /// </summary>
-        [DataMember(Name = "TestCollectionEndingWithWordList", EmitDefaultValue = false)]
+        [DataMember(Name = "TestCollectionEndingWithWordList", EmitDefaultValue = true)]
         public List<TestCollectionEndingWithWordList> TestCollectionEndingWithWordList
         {
             get{ return _TestCollectionEndingWithWordList;}

samples/client/petstore/csharp-netcore/OpenAPIClient-ConditionalSerialization/src/Org.OpenAPITools/Model/User.cs

@@ -139,7 +139,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Username
         /// </summary>
-        [DataMember(Name = "username", EmitDefaultValue = false)]
+        [DataMember(Name = "username", EmitDefaultValue = true)]
         public string Username
         {
             get{ return _Username;}
@@ -163,7 +163,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets FirstName
         /// </summary>
-        [DataMember(Name = "firstName", EmitDefaultValue = false)]
+        [DataMember(Name = "firstName", EmitDefaultValue = true)]
         public string FirstName
         {
             get{ return _FirstName;}
@@ -187,7 +187,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets LastName
         /// </summary>
-        [DataMember(Name = "lastName", EmitDefaultValue = false)]
+        [DataMember(Name = "lastName", EmitDefaultValue = true)]
         public string LastName
         {
             get{ return _LastName;}
@@ -211,7 +211,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Email
         /// </summary>
-        [DataMember(Name = "email", EmitDefaultValue = false)]
+        [DataMember(Name = "email", EmitDefaultValue = true)]
         public string Email
         {
             get{ return _Email;}
@@ -235,7 +235,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Password
         /// </summary>
-        [DataMember(Name = "password", EmitDefaultValue = false)]
+        [DataMember(Name = "password", EmitDefaultValue = true)]
         public string Password
         {
             get{ return _Password;}
@@ -259,7 +259,7 @@ namespace Org.OpenAPITools.Model
         /// <summary>
         /// Gets or Sets Phone
         /// </summary>
-        [DataMember(Name = "phone", EmitDefaultValue = false)]
+        [DataMember(Name = "phone", EmitDefaultValue = true)]
         public string Phone
         {
             get{ return _Phone;}
@@ -309,7 +309,7 @@ namespace Org.OpenAPITools.Model
         /// test code generation for objects Value must be a map of strings to values. It cannot be the &#39;null&#39; value.
         /// </summary>
         /// <value>test code generation for objects Value must be a map of strings to values. It cannot be the &#39;null&#39; value.</value>
-        [DataMember(Name = "objectWithNoDeclaredProps", EmitDefaultValue = false)]
+        [DataMember(Name = "objectWithNoDeclaredProps", EmitDefaultValue = true)]
         public Object ObjectWithNoDeclaredProps
         {
             get{ return _ObjectWithNoDeclaredProps;}

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/AnotherFakeApi.cs

@@ -39,7 +39,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;ModelClient&gt;&gt;</returns>
-        Task<ApiResponse<ModelClient>> Call123TestSpecialTagsAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<ModelClient>> Call123TestSpecialTagsAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// To test special tags
@@ -50,7 +50,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;ModelClient&gt;?&gt;</returns>
-        Task<ApiResponse<ModelClient>?> Call123TestSpecialTagsOrDefaultAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<ModelClient>?> Call123TestSpecialTagsOrDefaultAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default);
     }
 }
 
@@ -128,7 +128,7 @@ namespace Org.OpenAPITools.Api
             Logger.LogInformation("{0,-9} | {1} | {3}", (args.ReceivedAt - args.RequestedAt).TotalSeconds, args.HttpStatus, args.Path);
         }
 
-        partial void FormatCall123TestSpecialTags(ModelClient modelClient);
+        partial void FormatCall123TestSpecialTags(ModelClient? modelClient);
 
         /// <summary>
         /// Validates the request parameters
@@ -152,7 +152,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="modelClient"></param>
-        protected virtual void AfterCall123TestSpecialTags(ApiResponse<ModelClient> apiResponseLocalVar, ModelClient modelClient)
+        protected virtual void AfterCall123TestSpecialTags(ApiResponse<ModelClient> apiResponseLocalVar, ModelClient? modelClient)
         {
         }
 
@@ -163,7 +163,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="modelClient"></param>
-        protected virtual void OnErrorCall123TestSpecialTags(Exception exception, string pathFormat, string path, ModelClient modelClient)
+        protected virtual void OnErrorCall123TestSpecialTags(Exception exception, string pathFormat, string path, ModelClient? modelClient)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -174,7 +174,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="ModelClient"/></returns>
-        public async Task<ApiResponse<ModelClient>?> Call123TestSpecialTagsOrDefaultAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<ModelClient>?> Call123TestSpecialTagsOrDefaultAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -193,7 +193,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="ModelClient"/></returns>
-        public async Task<ApiResponse<ModelClient>> Call123TestSpecialTagsAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<ModelClient>> Call123TestSpecialTagsAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/DefaultApi.cs

@@ -60,7 +60,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="country"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> GetCountryAsync(string country, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> GetCountryAsync(string? country = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// 
@@ -71,7 +71,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="country"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> GetCountryOrDefaultAsync(string country, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> GetCountryOrDefaultAsync(string? country = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Hello
@@ -263,7 +263,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatGetCountry(ref string country);
+        partial void FormatGetCountry(ref string? country);
 
         /// <summary>
         /// Validates the request parameters
@@ -287,7 +287,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="country"></param>
-        protected virtual void AfterGetCountry(ApiResponse<object> apiResponseLocalVar, string country)
+        protected virtual void AfterGetCountry(ApiResponse<object> apiResponseLocalVar, string? country)
         {
         }
 
@@ -298,7 +298,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="country"></param>
-        protected virtual void OnErrorGetCountry(Exception exception, string pathFormat, string path, string country)
+        protected virtual void OnErrorGetCountry(Exception exception, string pathFormat, string path, string? country)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -309,7 +309,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="country"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> GetCountryOrDefaultAsync(string country, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> GetCountryOrDefaultAsync(string? country = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -328,7 +328,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="country"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> GetCountryAsync(string country, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> GetCountryAsync(string? country = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/FakeApi.cs

@@ -175,7 +175,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="fileSchemaTestClass"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> TestBodyWithFileSchemaAsync(FileSchemaTestClass fileSchemaTestClass, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> TestBodyWithFileSchemaAsync(FileSchemaTestClass? fileSchemaTestClass = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// 
@@ -186,7 +186,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="fileSchemaTestClass"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> TestBodyWithFileSchemaOrDefaultAsync(FileSchemaTestClass fileSchemaTestClass, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> TestBodyWithFileSchemaOrDefaultAsync(FileSchemaTestClass? fileSchemaTestClass = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// 
@@ -199,7 +199,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="query"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> TestBodyWithQueryParamsAsync(User user, string query, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> TestBodyWithQueryParamsAsync(User? user = null, string? query = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// 
@@ -211,7 +211,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="query"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> TestBodyWithQueryParamsOrDefaultAsync(User user, string query, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> TestBodyWithQueryParamsOrDefaultAsync(User? user = null, string? query = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// To test \&quot;client\&quot; model
@@ -223,7 +223,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;ModelClient&gt;&gt;</returns>
-        Task<ApiResponse<ModelClient>> TestClientModelAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<ModelClient>> TestClientModelAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// To test \&quot;client\&quot; model
@@ -234,7 +234,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;ModelClient&gt;?&gt;</returns>
-        Task<ApiResponse<ModelClient>?> TestClientModelOrDefaultAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<ModelClient>?> TestClientModelOrDefaultAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
@@ -259,7 +259,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="dateTime">None (optional, default to &quot;2010-02-01T10:20:10.111110+01:00&quot;)</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> TestEndpointParametersAsync(byte[] varByte, decimal number, double varDouble, string patternWithoutDelimiter, DateTime? date = null, System.IO.Stream? binary = null, float? varFloat = null, int? integer = null, int? int32 = null, long? int64 = null, string? varString = null, string? password = null, string? callback = null, DateTime? dateTime = null, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> TestEndpointParametersAsync(byte[]? varByte = null, decimal number, double varDouble, string? patternWithoutDelimiter = null, DateTime? date = null, System.IO.Stream? binary = null, float? varFloat = null, int? integer = null, int? int32 = null, long? int64 = null, string? varString = null, string? password = null, string? callback = null, DateTime? dateTime = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
@@ -283,7 +283,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="dateTime">None (optional, default to &quot;2010-02-01T10:20:10.111110+01:00&quot;)</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> TestEndpointParametersOrDefaultAsync(byte[] varByte, decimal number, double varDouble, string patternWithoutDelimiter, DateTime? date = null, System.IO.Stream? binary = null, float? varFloat = null, int? integer = null, int? int32 = null, long? int64 = null, string? varString = null, string? password = null, string? callback = null, DateTime? dateTime = null, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> TestEndpointParametersOrDefaultAsync(byte[]? varByte = null, decimal number, double varDouble, string? patternWithoutDelimiter = null, DateTime? date = null, System.IO.Stream? binary = null, float? varFloat = null, int? integer = null, int? int32 = null, long? int64 = null, string? varString = null, string? password = null, string? callback = null, DateTime? dateTime = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// To test enum parameters
@@ -365,7 +365,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="requestBody">request body</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> TestInlineAdditionalPropertiesAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> TestInlineAdditionalPropertiesAsync(Dictionary<string, string>? requestBody = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// test inline additionalProperties
@@ -376,7 +376,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="requestBody">request body</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> TestInlineAdditionalPropertiesOrDefaultAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> TestInlineAdditionalPropertiesOrDefaultAsync(Dictionary<string, string>? requestBody = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// test json serialization of form data
@@ -389,7 +389,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="param2">field2</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> TestJsonFormDataAsync(string param, string param2, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> TestJsonFormDataAsync(string? param = null, string? param2 = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// test json serialization of form data
@@ -401,7 +401,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="param2">field2</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> TestJsonFormDataOrDefaultAsync(string param, string param2, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> TestJsonFormDataOrDefaultAsync(string? param = null, string? param2 = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// 
@@ -417,7 +417,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="context"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> TestQueryParameterCollectionFormatAsync(List<string> pipe, List<string> ioutil, List<string> http, List<string> url, List<string> context, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> TestQueryParameterCollectionFormatAsync(List<string>? pipe = null, List<string>? ioutil = null, List<string>? http = null, List<string>? url = null, List<string>? context = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// 
@@ -432,7 +432,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="context"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> TestQueryParameterCollectionFormatOrDefaultAsync(List<string> pipe, List<string> ioutil, List<string> http, List<string> url, List<string> context, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> TestQueryParameterCollectionFormatOrDefaultAsync(List<string>? pipe = null, List<string>? ioutil = null, List<string>? http = null, List<string>? url = null, List<string>? context = null, System.Threading.CancellationToken cancellationToken = default);
     }
 }
 
@@ -1182,7 +1182,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatTestBodyWithFileSchema(FileSchemaTestClass fileSchemaTestClass);
+        partial void FormatTestBodyWithFileSchema(FileSchemaTestClass? fileSchemaTestClass);
 
         /// <summary>
         /// Validates the request parameters
@@ -1206,7 +1206,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="fileSchemaTestClass"></param>
-        protected virtual void AfterTestBodyWithFileSchema(ApiResponse<object> apiResponseLocalVar, FileSchemaTestClass fileSchemaTestClass)
+        protected virtual void AfterTestBodyWithFileSchema(ApiResponse<object> apiResponseLocalVar, FileSchemaTestClass? fileSchemaTestClass)
         {
         }
 
@@ -1217,7 +1217,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="fileSchemaTestClass"></param>
-        protected virtual void OnErrorTestBodyWithFileSchema(Exception exception, string pathFormat, string path, FileSchemaTestClass fileSchemaTestClass)
+        protected virtual void OnErrorTestBodyWithFileSchema(Exception exception, string pathFormat, string path, FileSchemaTestClass? fileSchemaTestClass)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -1228,7 +1228,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="fileSchemaTestClass"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> TestBodyWithFileSchemaOrDefaultAsync(FileSchemaTestClass fileSchemaTestClass, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> TestBodyWithFileSchemaOrDefaultAsync(FileSchemaTestClass? fileSchemaTestClass = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -1247,7 +1247,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="fileSchemaTestClass"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> TestBodyWithFileSchemaAsync(FileSchemaTestClass fileSchemaTestClass, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> TestBodyWithFileSchemaAsync(FileSchemaTestClass? fileSchemaTestClass = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -1306,7 +1306,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatTestBodyWithQueryParams(User user, ref string query);
+        partial void FormatTestBodyWithQueryParams(User? user, ref string? query);
 
         /// <summary>
         /// Validates the request parameters
@@ -1335,7 +1335,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="user"></param>
         /// <param name="query"></param>
-        protected virtual void AfterTestBodyWithQueryParams(ApiResponse<object> apiResponseLocalVar, User user, string query)
+        protected virtual void AfterTestBodyWithQueryParams(ApiResponse<object> apiResponseLocalVar, User? user, string? query)
         {
         }
 
@@ -1347,7 +1347,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="path"></param>
         /// <param name="user"></param>
         /// <param name="query"></param>
-        protected virtual void OnErrorTestBodyWithQueryParams(Exception exception, string pathFormat, string path, User user, string query)
+        protected virtual void OnErrorTestBodyWithQueryParams(Exception exception, string pathFormat, string path, User? user, string? query)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -1359,7 +1359,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="query"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> TestBodyWithQueryParamsOrDefaultAsync(User user, string query, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> TestBodyWithQueryParamsOrDefaultAsync(User? user = null, string? query = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -1379,7 +1379,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="query"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> TestBodyWithQueryParamsAsync(User user, string query, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> TestBodyWithQueryParamsAsync(User? user = null, string? query = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -1444,7 +1444,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatTestClientModel(ModelClient modelClient);
+        partial void FormatTestClientModel(ModelClient? modelClient);
 
         /// <summary>
         /// Validates the request parameters
@@ -1468,7 +1468,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="modelClient"></param>
-        protected virtual void AfterTestClientModel(ApiResponse<ModelClient> apiResponseLocalVar, ModelClient modelClient)
+        protected virtual void AfterTestClientModel(ApiResponse<ModelClient> apiResponseLocalVar, ModelClient? modelClient)
         {
         }
 
@@ -1479,7 +1479,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="modelClient"></param>
-        protected virtual void OnErrorTestClientModel(Exception exception, string pathFormat, string path, ModelClient modelClient)
+        protected virtual void OnErrorTestClientModel(Exception exception, string pathFormat, string path, ModelClient? modelClient)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -1490,7 +1490,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="ModelClient"/></returns>
-        public async Task<ApiResponse<ModelClient>?> TestClientModelOrDefaultAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<ModelClient>?> TestClientModelOrDefaultAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -1509,7 +1509,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="ModelClient"/></returns>
-        public async Task<ApiResponse<ModelClient>> TestClientModelAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<ModelClient>> TestClientModelAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -1577,7 +1577,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatTestEndpointParameters(ref byte[] varByte, ref decimal number, ref double varDouble, ref string patternWithoutDelimiter, ref DateTime? date, ref System.IO.Stream? binary, ref float? varFloat, ref int? integer, ref int? int32, ref long? int64, ref string? varString, ref string? password, ref string? callback, ref DateTime? dateTime);
+        partial void FormatTestEndpointParameters(ref byte[]? varByte, ref decimal number, ref double varDouble, ref string? patternWithoutDelimiter, ref DateTime? date, ref System.IO.Stream? binary, ref float? varFloat, ref int? integer, ref int? int32, ref long? int64, ref string? varString, ref string? password, ref string? callback, ref DateTime? dateTime);
 
         /// <summary>
         /// Validates the request parameters
@@ -1636,7 +1636,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="password"></param>
         /// <param name="callback"></param>
         /// <param name="dateTime"></param>
-        protected virtual void AfterTestEndpointParameters(ApiResponse<object> apiResponseLocalVar, byte[] varByte, decimal number, double varDouble, string patternWithoutDelimiter, DateTime? date, System.IO.Stream? binary, float? varFloat, int? integer, int? int32, long? int64, string? varString, string? password, string? callback, DateTime? dateTime)
+        protected virtual void AfterTestEndpointParameters(ApiResponse<object> apiResponseLocalVar, byte[]? varByte, decimal number, double varDouble, string? patternWithoutDelimiter, DateTime? date, System.IO.Stream? binary, float? varFloat, int? integer, int? int32, long? int64, string? varString, string? password, string? callback, DateTime? dateTime)
         {
         }
 
@@ -1660,7 +1660,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="password"></param>
         /// <param name="callback"></param>
         /// <param name="dateTime"></param>
-        protected virtual void OnErrorTestEndpointParameters(Exception exception, string pathFormat, string path, byte[] varByte, decimal number, double varDouble, string patternWithoutDelimiter, DateTime? date, System.IO.Stream? binary, float? varFloat, int? integer, int? int32, long? int64, string? varString, string? password, string? callback, DateTime? dateTime)
+        protected virtual void OnErrorTestEndpointParameters(Exception exception, string pathFormat, string path, byte[]? varByte, decimal number, double varDouble, string? patternWithoutDelimiter, DateTime? date, System.IO.Stream? binary, float? varFloat, int? integer, int? int32, long? int64, string? varString, string? password, string? callback, DateTime? dateTime)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -1684,7 +1684,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="dateTime">None (optional, default to &quot;2010-02-01T10:20:10.111110+01:00&quot;)</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> TestEndpointParametersOrDefaultAsync(byte[] varByte, decimal number, double varDouble, string patternWithoutDelimiter, DateTime? date = null, System.IO.Stream? binary = null, float? varFloat = null, int? integer = null, int? int32 = null, long? int64 = null, string? varString = null, string? password = null, string? callback = null, DateTime? dateTime = null, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> TestEndpointParametersOrDefaultAsync(byte[]? varByte = null, decimal number, double varDouble, string? patternWithoutDelimiter = null, DateTime? date = null, System.IO.Stream? binary = null, float? varFloat = null, int? integer = null, int? int32 = null, long? int64 = null, string? varString = null, string? password = null, string? callback = null, DateTime? dateTime = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -1716,7 +1716,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="dateTime">None (optional, default to &quot;2010-02-01T10:20:10.111110+01:00&quot;)</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> TestEndpointParametersAsync(byte[] varByte, decimal number, double varDouble, string patternWithoutDelimiter, DateTime? date = null, System.IO.Stream? binary = null, float? varFloat = null, int? integer = null, int? int32 = null, long? int64 = null, string? varString = null, string? password = null, string? callback = null, DateTime? dateTime = null, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> TestEndpointParametersAsync(byte[]? varByte = null, decimal number, double varDouble, string? patternWithoutDelimiter = null, DateTime? date = null, System.IO.Stream? binary = null, float? varFloat = null, int? integer = null, int? int32 = null, long? int64 = null, string? varString = null, string? password = null, string? callback = null, DateTime? dateTime = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -2169,7 +2169,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatTestInlineAdditionalProperties(Dictionary<string, string> requestBody);
+        partial void FormatTestInlineAdditionalProperties(Dictionary<string, string>? requestBody);
 
         /// <summary>
         /// Validates the request parameters
@@ -2193,7 +2193,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="requestBody"></param>
-        protected virtual void AfterTestInlineAdditionalProperties(ApiResponse<object> apiResponseLocalVar, Dictionary<string, string> requestBody)
+        protected virtual void AfterTestInlineAdditionalProperties(ApiResponse<object> apiResponseLocalVar, Dictionary<string, string>? requestBody)
         {
         }
 
@@ -2204,7 +2204,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="requestBody"></param>
-        protected virtual void OnErrorTestInlineAdditionalProperties(Exception exception, string pathFormat, string path, Dictionary<string, string> requestBody)
+        protected virtual void OnErrorTestInlineAdditionalProperties(Exception exception, string pathFormat, string path, Dictionary<string, string>? requestBody)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -2215,7 +2215,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="requestBody">request body</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> TestInlineAdditionalPropertiesOrDefaultAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> TestInlineAdditionalPropertiesOrDefaultAsync(Dictionary<string, string>? requestBody = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -2234,7 +2234,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="requestBody">request body</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> TestInlineAdditionalPropertiesAsync(Dictionary<string, string> requestBody, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> TestInlineAdditionalPropertiesAsync(Dictionary<string, string>? requestBody = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -2293,7 +2293,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatTestJsonFormData(ref string param, ref string param2);
+        partial void FormatTestJsonFormData(ref string? param, ref string? param2);
 
         /// <summary>
         /// Validates the request parameters
@@ -2322,7 +2322,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="param"></param>
         /// <param name="param2"></param>
-        protected virtual void AfterTestJsonFormData(ApiResponse<object> apiResponseLocalVar, string param, string param2)
+        protected virtual void AfterTestJsonFormData(ApiResponse<object> apiResponseLocalVar, string? param, string? param2)
         {
         }
 
@@ -2334,7 +2334,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="path"></param>
         /// <param name="param"></param>
         /// <param name="param2"></param>
-        protected virtual void OnErrorTestJsonFormData(Exception exception, string pathFormat, string path, string param, string param2)
+        protected virtual void OnErrorTestJsonFormData(Exception exception, string pathFormat, string path, string? param, string? param2)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -2346,7 +2346,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="param2">field2</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> TestJsonFormDataOrDefaultAsync(string param, string param2, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> TestJsonFormDataOrDefaultAsync(string? param = null, string? param2 = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -2366,7 +2366,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="param2">field2</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> TestJsonFormDataAsync(string param, string param2, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> TestJsonFormDataAsync(string? param = null, string? param2 = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -2435,7 +2435,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatTestQueryParameterCollectionFormat(List<string> pipe, List<string> ioutil, List<string> http, List<string> url, List<string> context);
+        partial void FormatTestQueryParameterCollectionFormat(List<string>? pipe, List<string>? ioutil, List<string>? http, List<string>? url, List<string>? context);
 
         /// <summary>
         /// Validates the request parameters
@@ -2479,7 +2479,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="http"></param>
         /// <param name="url"></param>
         /// <param name="context"></param>
-        protected virtual void AfterTestQueryParameterCollectionFormat(ApiResponse<object> apiResponseLocalVar, List<string> pipe, List<string> ioutil, List<string> http, List<string> url, List<string> context)
+        protected virtual void AfterTestQueryParameterCollectionFormat(ApiResponse<object> apiResponseLocalVar, List<string>? pipe, List<string>? ioutil, List<string>? http, List<string>? url, List<string>? context)
         {
         }
 
@@ -2494,7 +2494,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="http"></param>
         /// <param name="url"></param>
         /// <param name="context"></param>
-        protected virtual void OnErrorTestQueryParameterCollectionFormat(Exception exception, string pathFormat, string path, List<string> pipe, List<string> ioutil, List<string> http, List<string> url, List<string> context)
+        protected virtual void OnErrorTestQueryParameterCollectionFormat(Exception exception, string pathFormat, string path, List<string>? pipe, List<string>? ioutil, List<string>? http, List<string>? url, List<string>? context)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -2509,7 +2509,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="context"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> TestQueryParameterCollectionFormatOrDefaultAsync(List<string> pipe, List<string> ioutil, List<string> http, List<string> url, List<string> context, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> TestQueryParameterCollectionFormatOrDefaultAsync(List<string>? pipe = null, List<string>? ioutil = null, List<string>? http = null, List<string>? url = null, List<string>? context = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -2532,7 +2532,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="context"></param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> TestQueryParameterCollectionFormatAsync(List<string> pipe, List<string> ioutil, List<string> http, List<string> url, List<string> context, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> TestQueryParameterCollectionFormatAsync(List<string>? pipe = null, List<string>? ioutil = null, List<string>? http = null, List<string>? url = null, List<string>? context = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/FakeClassnameTags123Api.cs

@@ -39,7 +39,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;ModelClient&gt;&gt;</returns>
-        Task<ApiResponse<ModelClient>> TestClassnameAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<ModelClient>> TestClassnameAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// To test class name in snake case
@@ -50,7 +50,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;ModelClient&gt;?&gt;</returns>
-        Task<ApiResponse<ModelClient>?> TestClassnameOrDefaultAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<ModelClient>?> TestClassnameOrDefaultAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default);
     }
 }
 
@@ -128,7 +128,7 @@ namespace Org.OpenAPITools.Api
             Logger.LogInformation("{0,-9} | {1} | {3}", (args.ReceivedAt - args.RequestedAt).TotalSeconds, args.HttpStatus, args.Path);
         }
 
-        partial void FormatTestClassname(ModelClient modelClient);
+        partial void FormatTestClassname(ModelClient? modelClient);
 
         /// <summary>
         /// Validates the request parameters
@@ -152,7 +152,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="modelClient"></param>
-        protected virtual void AfterTestClassname(ApiResponse<ModelClient> apiResponseLocalVar, ModelClient modelClient)
+        protected virtual void AfterTestClassname(ApiResponse<ModelClient> apiResponseLocalVar, ModelClient? modelClient)
         {
         }
 
@@ -163,7 +163,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="modelClient"></param>
-        protected virtual void OnErrorTestClassname(Exception exception, string pathFormat, string path, ModelClient modelClient)
+        protected virtual void OnErrorTestClassname(Exception exception, string pathFormat, string path, ModelClient? modelClient)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -174,7 +174,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="ModelClient"/></returns>
-        public async Task<ApiResponse<ModelClient>?> TestClassnameOrDefaultAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<ModelClient>?> TestClassnameOrDefaultAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -193,7 +193,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="modelClient">client model</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="ModelClient"/></returns>
-        public async Task<ApiResponse<ModelClient>> TestClassnameAsync(ModelClient modelClient, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<ModelClient>> TestClassnameAsync(ModelClient? modelClient = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/PetApi.cs

@@ -39,7 +39,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="pet">Pet object that needs to be added to the store</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> AddPetAsync(Pet pet, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> AddPetAsync(Pet? pet = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Add a new pet to the store
@@ -50,7 +50,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="pet">Pet object that needs to be added to the store</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> AddPetOrDefaultAsync(Pet pet, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> AddPetOrDefaultAsync(Pet? pet = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Deletes a pet
@@ -87,7 +87,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="status">Status values that need to be considered for filter</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;List&lt;Pet&gt;&gt;&gt;</returns>
-        Task<ApiResponse<List<Pet>>> FindPetsByStatusAsync(List<string> status, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<List<Pet>>> FindPetsByStatusAsync(List<string>? status = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Finds Pets by status
@@ -98,7 +98,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="status">Status values that need to be considered for filter</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;List&lt;Pet&gt;&gt;?&gt;</returns>
-        Task<ApiResponse<List<Pet>>?> FindPetsByStatusOrDefaultAsync(List<string> status, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<List<Pet>>?> FindPetsByStatusOrDefaultAsync(List<string>? status = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Finds Pets by tags
@@ -110,7 +110,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="tags">Tags to filter by</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;List&lt;Pet&gt;&gt;&gt;</returns>
-        Task<ApiResponse<List<Pet>>> FindPetsByTagsAsync(List<string> tags, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<List<Pet>>> FindPetsByTagsAsync(List<string>? tags = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Finds Pets by tags
@@ -121,7 +121,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="tags">Tags to filter by</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;List&lt;Pet&gt;&gt;?&gt;</returns>
-        Task<ApiResponse<List<Pet>>?> FindPetsByTagsOrDefaultAsync(List<string> tags, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<List<Pet>>?> FindPetsByTagsOrDefaultAsync(List<string>? tags = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Find pet by ID
@@ -156,7 +156,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="pet">Pet object that needs to be added to the store</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> UpdatePetAsync(Pet pet, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> UpdatePetAsync(Pet? pet = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Update an existing pet
@@ -167,7 +167,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="pet">Pet object that needs to be added to the store</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> UpdatePetOrDefaultAsync(Pet pet, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> UpdatePetOrDefaultAsync(Pet? pet = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Updates a pet in the store with form data
@@ -235,7 +235,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="additionalMetadata">Additional data to pass to server (optional)</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;ApiResponse&gt;&gt;</returns>
-        Task<ApiResponse<ApiResponse>> UploadFileWithRequiredFileAsync(System.IO.Stream requiredFile, long petId, string? additionalMetadata = null, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<ApiResponse>> UploadFileWithRequiredFileAsync(System.IO.Stream? requiredFile = null, long petId, string? additionalMetadata = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// uploads an image (required)
@@ -248,7 +248,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="additionalMetadata">Additional data to pass to server (optional)</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;ApiResponse&gt;?&gt;</returns>
-        Task<ApiResponse<ApiResponse>?> UploadFileWithRequiredFileOrDefaultAsync(System.IO.Stream requiredFile, long petId, string? additionalMetadata = null, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<ApiResponse>?> UploadFileWithRequiredFileOrDefaultAsync(System.IO.Stream? requiredFile = null, long petId, string? additionalMetadata = null, System.Threading.CancellationToken cancellationToken = default);
     }
 }
 
@@ -326,7 +326,7 @@ namespace Org.OpenAPITools.Api
             Logger.LogInformation("{0,-9} | {1} | {3}", (args.ReceivedAt - args.RequestedAt).TotalSeconds, args.HttpStatus, args.Path);
         }
 
-        partial void FormatAddPet(Pet pet);
+        partial void FormatAddPet(Pet? pet);
 
         /// <summary>
         /// Validates the request parameters
@@ -350,7 +350,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="pet"></param>
-        protected virtual void AfterAddPet(ApiResponse<object> apiResponseLocalVar, Pet pet)
+        protected virtual void AfterAddPet(ApiResponse<object> apiResponseLocalVar, Pet? pet)
         {
         }
 
@@ -361,7 +361,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="pet"></param>
-        protected virtual void OnErrorAddPet(Exception exception, string pathFormat, string path, Pet pet)
+        protected virtual void OnErrorAddPet(Exception exception, string pathFormat, string path, Pet? pet)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -372,7 +372,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pet">Pet object that needs to be added to the store</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> AddPetOrDefaultAsync(Pet pet, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> AddPetOrDefaultAsync(Pet? pet = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -391,7 +391,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pet">Pet object that needs to be added to the store</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> AddPetAsync(Pet pet, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> AddPetAsync(Pet? pet = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -606,7 +606,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatFindPetsByStatus(List<string> status);
+        partial void FormatFindPetsByStatus(List<string>? status);
 
         /// <summary>
         /// Validates the request parameters
@@ -630,7 +630,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="status"></param>
-        protected virtual void AfterFindPetsByStatus(ApiResponse<List<Pet>> apiResponseLocalVar, List<string> status)
+        protected virtual void AfterFindPetsByStatus(ApiResponse<List<Pet>> apiResponseLocalVar, List<string>? status)
         {
         }
 
@@ -641,7 +641,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="status"></param>
-        protected virtual void OnErrorFindPetsByStatus(Exception exception, string pathFormat, string path, List<string> status)
+        protected virtual void OnErrorFindPetsByStatus(Exception exception, string pathFormat, string path, List<string>? status)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -652,7 +652,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="status">Status values that need to be considered for filter</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="List&lt;Pet&gt;"/></returns>
-        public async Task<ApiResponse<List<Pet>>?> FindPetsByStatusOrDefaultAsync(List<string> status, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<List<Pet>>?> FindPetsByStatusOrDefaultAsync(List<string>? status = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -671,7 +671,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="status">Status values that need to be considered for filter</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="List&lt;Pet&gt;"/></returns>
-        public async Task<ApiResponse<List<Pet>>> FindPetsByStatusAsync(List<string> status, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<List<Pet>>> FindPetsByStatusAsync(List<string>? status = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -757,7 +757,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatFindPetsByTags(List<string> tags);
+        partial void FormatFindPetsByTags(List<string>? tags);
 
         /// <summary>
         /// Validates the request parameters
@@ -781,7 +781,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="tags"></param>
-        protected virtual void AfterFindPetsByTags(ApiResponse<List<Pet>> apiResponseLocalVar, List<string> tags)
+        protected virtual void AfterFindPetsByTags(ApiResponse<List<Pet>> apiResponseLocalVar, List<string>? tags)
         {
         }
 
@@ -792,7 +792,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="tags"></param>
-        protected virtual void OnErrorFindPetsByTags(Exception exception, string pathFormat, string path, List<string> tags)
+        protected virtual void OnErrorFindPetsByTags(Exception exception, string pathFormat, string path, List<string>? tags)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -803,7 +803,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="tags">Tags to filter by</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="List&lt;Pet&gt;"/></returns>
-        public async Task<ApiResponse<List<Pet>>?> FindPetsByTagsOrDefaultAsync(List<string> tags, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<List<Pet>>?> FindPetsByTagsOrDefaultAsync(List<string>? tags = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -822,7 +822,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="tags">Tags to filter by</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="List&lt;Pet&gt;"/></returns>
-        public async Task<ApiResponse<List<Pet>>> FindPetsByTagsAsync(List<string> tags, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<List<Pet>>> FindPetsByTagsAsync(List<string>? tags = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -1039,7 +1039,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatUpdatePet(Pet pet);
+        partial void FormatUpdatePet(Pet? pet);
 
         /// <summary>
         /// Validates the request parameters
@@ -1063,7 +1063,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="pet"></param>
-        protected virtual void AfterUpdatePet(ApiResponse<object> apiResponseLocalVar, Pet pet)
+        protected virtual void AfterUpdatePet(ApiResponse<object> apiResponseLocalVar, Pet? pet)
         {
         }
 
@@ -1074,7 +1074,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="pet"></param>
-        protected virtual void OnErrorUpdatePet(Exception exception, string pathFormat, string path, Pet pet)
+        protected virtual void OnErrorUpdatePet(Exception exception, string pathFormat, string path, Pet? pet)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -1085,7 +1085,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pet">Pet object that needs to be added to the store</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> UpdatePetOrDefaultAsync(Pet pet, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> UpdatePetOrDefaultAsync(Pet? pet = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -1104,7 +1104,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pet">Pet object that needs to be added to the store</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> UpdatePetAsync(Pet pet, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> UpdatePetAsync(Pet? pet = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -1505,7 +1505,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatUploadFileWithRequiredFile(ref System.IO.Stream requiredFile, ref long petId, ref string? additionalMetadata);
+        partial void FormatUploadFileWithRequiredFile(ref System.IO.Stream? requiredFile, ref long petId, ref string? additionalMetadata);
 
         /// <summary>
         /// Validates the request parameters
@@ -1536,7 +1536,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="requiredFile"></param>
         /// <param name="petId"></param>
         /// <param name="additionalMetadata"></param>
-        protected virtual void AfterUploadFileWithRequiredFile(ApiResponse<ApiResponse> apiResponseLocalVar, System.IO.Stream requiredFile, long petId, string? additionalMetadata)
+        protected virtual void AfterUploadFileWithRequiredFile(ApiResponse<ApiResponse> apiResponseLocalVar, System.IO.Stream? requiredFile, long petId, string? additionalMetadata)
         {
         }
 
@@ -1549,7 +1549,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="requiredFile"></param>
         /// <param name="petId"></param>
         /// <param name="additionalMetadata"></param>
-        protected virtual void OnErrorUploadFileWithRequiredFile(Exception exception, string pathFormat, string path, System.IO.Stream requiredFile, long petId, string? additionalMetadata)
+        protected virtual void OnErrorUploadFileWithRequiredFile(Exception exception, string pathFormat, string path, System.IO.Stream? requiredFile, long petId, string? additionalMetadata)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -1562,7 +1562,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="additionalMetadata">Additional data to pass to server (optional)</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="ApiResponse"/></returns>
-        public async Task<ApiResponse<ApiResponse>?> UploadFileWithRequiredFileOrDefaultAsync(System.IO.Stream requiredFile, long petId, string? additionalMetadata = null, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<ApiResponse>?> UploadFileWithRequiredFileOrDefaultAsync(System.IO.Stream? requiredFile = null, long petId, string? additionalMetadata = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -1583,7 +1583,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="additionalMetadata">Additional data to pass to server (optional)</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="ApiResponse"/></returns>
-        public async Task<ApiResponse<ApiResponse>> UploadFileWithRequiredFileAsync(System.IO.Stream requiredFile, long petId, string? additionalMetadata = null, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<ApiResponse>> UploadFileWithRequiredFileAsync(System.IO.Stream? requiredFile = null, long petId, string? additionalMetadata = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/StoreApi.cs

@@ -39,7 +39,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="orderId">ID of the order that needs to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> DeleteOrderAsync(string orderId, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> DeleteOrderAsync(string? orderId = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Delete purchase order by ID
@@ -50,7 +50,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="orderId">ID of the order that needs to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> DeleteOrderOrDefaultAsync(string orderId, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> DeleteOrderOrDefaultAsync(string? orderId = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Returns pet inventories by status
@@ -106,7 +106,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="order">order placed for purchasing the pet</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;Order&gt;&gt;</returns>
-        Task<ApiResponse<Order>> PlaceOrderAsync(Order order, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<Order>> PlaceOrderAsync(Order? order = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Place an order for a pet
@@ -117,7 +117,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="order">order placed for purchasing the pet</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;Order&gt;?&gt;</returns>
-        Task<ApiResponse<Order>?> PlaceOrderOrDefaultAsync(Order order, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<Order>?> PlaceOrderOrDefaultAsync(Order? order = null, System.Threading.CancellationToken cancellationToken = default);
     }
 }
 
@@ -195,7 +195,7 @@ namespace Org.OpenAPITools.Api
             Logger.LogInformation("{0,-9} | {1} | {3}", (args.ReceivedAt - args.RequestedAt).TotalSeconds, args.HttpStatus, args.Path);
         }
 
-        partial void FormatDeleteOrder(ref string orderId);
+        partial void FormatDeleteOrder(ref string? orderId);
 
         /// <summary>
         /// Validates the request parameters
@@ -219,7 +219,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="orderId"></param>
-        protected virtual void AfterDeleteOrder(ApiResponse<object> apiResponseLocalVar, string orderId)
+        protected virtual void AfterDeleteOrder(ApiResponse<object> apiResponseLocalVar, string? orderId)
         {
         }
 
@@ -230,7 +230,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="orderId"></param>
-        protected virtual void OnErrorDeleteOrder(Exception exception, string pathFormat, string path, string orderId)
+        protected virtual void OnErrorDeleteOrder(Exception exception, string pathFormat, string path, string? orderId)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -241,7 +241,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="orderId">ID of the order that needs to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> DeleteOrderOrDefaultAsync(string orderId, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> DeleteOrderOrDefaultAsync(string? orderId = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -260,7 +260,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="orderId">ID of the order that needs to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> DeleteOrderAsync(string orderId, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> DeleteOrderAsync(string? orderId = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -530,7 +530,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatPlaceOrder(Order order);
+        partial void FormatPlaceOrder(Order? order);
 
         /// <summary>
         /// Validates the request parameters
@@ -554,7 +554,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="order"></param>
-        protected virtual void AfterPlaceOrder(ApiResponse<Order> apiResponseLocalVar, Order order)
+        protected virtual void AfterPlaceOrder(ApiResponse<Order> apiResponseLocalVar, Order? order)
         {
         }
 
@@ -565,7 +565,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="order"></param>
-        protected virtual void OnErrorPlaceOrder(Exception exception, string pathFormat, string path, Order order)
+        protected virtual void OnErrorPlaceOrder(Exception exception, string pathFormat, string path, Order? order)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -576,7 +576,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="order">order placed for purchasing the pet</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="Order"/></returns>
-        public async Task<ApiResponse<Order>?> PlaceOrderOrDefaultAsync(Order order, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<Order>?> PlaceOrderOrDefaultAsync(Order? order = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -595,7 +595,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="order">order placed for purchasing the pet</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="Order"/></returns>
-        public async Task<ApiResponse<Order>> PlaceOrderAsync(Order order, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<Order>> PlaceOrderAsync(Order? order = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Api/UserApi.cs

@@ -39,7 +39,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="user">Created user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> CreateUserAsync(User user, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> CreateUserAsync(User? user = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Create user
@@ -50,7 +50,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="user">Created user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> CreateUserOrDefaultAsync(User user, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> CreateUserOrDefaultAsync(User? user = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Creates list of users with given input array
@@ -62,7 +62,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="user">List of user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> CreateUsersWithArrayInputAsync(List<User> user, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> CreateUsersWithArrayInputAsync(List<User>? user = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Creates list of users with given input array
@@ -73,7 +73,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="user">List of user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> CreateUsersWithArrayInputOrDefaultAsync(List<User> user, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> CreateUsersWithArrayInputOrDefaultAsync(List<User>? user = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Creates list of users with given input array
@@ -85,7 +85,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="user">List of user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> CreateUsersWithListInputAsync(List<User> user, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> CreateUsersWithListInputAsync(List<User>? user = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Creates list of users with given input array
@@ -96,7 +96,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="user">List of user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> CreateUsersWithListInputOrDefaultAsync(List<User> user, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> CreateUsersWithListInputOrDefaultAsync(List<User>? user = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Delete user
@@ -108,7 +108,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="username">The name that needs to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> DeleteUserAsync(string username, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> DeleteUserAsync(string? username = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Delete user
@@ -119,7 +119,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="username">The name that needs to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> DeleteUserOrDefaultAsync(string username, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> DeleteUserOrDefaultAsync(string? username = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Get user by user name
@@ -131,7 +131,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="username">The name that needs to be fetched. Use user1 for testing.</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;User&gt;&gt;</returns>
-        Task<ApiResponse<User>> GetUserByNameAsync(string username, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<User>> GetUserByNameAsync(string? username = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Get user by user name
@@ -142,7 +142,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="username">The name that needs to be fetched. Use user1 for testing.</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;User&gt;?&gt;</returns>
-        Task<ApiResponse<User>?> GetUserByNameOrDefaultAsync(string username, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<User>?> GetUserByNameOrDefaultAsync(string? username = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Logs user into the system
@@ -155,7 +155,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="password">The password for login in clear text</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;string&gt;&gt;</returns>
-        Task<ApiResponse<string>> LoginUserAsync(string username, string password, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<string>> LoginUserAsync(string? username = null, string? password = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Logs user into the system
@@ -167,7 +167,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="password">The password for login in clear text</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;string&gt;?&gt;</returns>
-        Task<ApiResponse<string>?> LoginUserOrDefaultAsync(string username, string password, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<string>?> LoginUserOrDefaultAsync(string? username = null, string? password = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Logs out current logged in user session
@@ -201,7 +201,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="username">name that need to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&lt;object&gt;&gt;</returns>
-        Task<ApiResponse<object>> UpdateUserAsync(User user, string username, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>> UpdateUserAsync(User? user = null, string? username = null, System.Threading.CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Updated user
@@ -213,7 +213,7 @@ namespace Org.OpenAPITools.IApi
         /// <param name="username">name that need to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns>Task&lt;ApiResponse&gt;object&gt;?&gt;</returns>
-        Task<ApiResponse<object>?> UpdateUserOrDefaultAsync(User user, string username, System.Threading.CancellationToken cancellationToken = default);
+        Task<ApiResponse<object>?> UpdateUserOrDefaultAsync(User? user = null, string? username = null, System.Threading.CancellationToken cancellationToken = default);
     }
 }
 
@@ -291,7 +291,7 @@ namespace Org.OpenAPITools.Api
             Logger.LogInformation("{0,-9} | {1} | {3}", (args.ReceivedAt - args.RequestedAt).TotalSeconds, args.HttpStatus, args.Path);
         }
 
-        partial void FormatCreateUser(User user);
+        partial void FormatCreateUser(User? user);
 
         /// <summary>
         /// Validates the request parameters
@@ -315,7 +315,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="user"></param>
-        protected virtual void AfterCreateUser(ApiResponse<object> apiResponseLocalVar, User user)
+        protected virtual void AfterCreateUser(ApiResponse<object> apiResponseLocalVar, User? user)
         {
         }
 
@@ -326,7 +326,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="user"></param>
-        protected virtual void OnErrorCreateUser(Exception exception, string pathFormat, string path, User user)
+        protected virtual void OnErrorCreateUser(Exception exception, string pathFormat, string path, User? user)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -337,7 +337,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="user">Created user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> CreateUserOrDefaultAsync(User user, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> CreateUserOrDefaultAsync(User? user = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -356,7 +356,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="user">Created user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> CreateUserAsync(User user, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> CreateUserAsync(User? user = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -415,7 +415,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatCreateUsersWithArrayInput(List<User> user);
+        partial void FormatCreateUsersWithArrayInput(List<User>? user);
 
         /// <summary>
         /// Validates the request parameters
@@ -439,7 +439,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="user"></param>
-        protected virtual void AfterCreateUsersWithArrayInput(ApiResponse<object> apiResponseLocalVar, List<User> user)
+        protected virtual void AfterCreateUsersWithArrayInput(ApiResponse<object> apiResponseLocalVar, List<User>? user)
         {
         }
 
@@ -450,7 +450,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="user"></param>
-        protected virtual void OnErrorCreateUsersWithArrayInput(Exception exception, string pathFormat, string path, List<User> user)
+        protected virtual void OnErrorCreateUsersWithArrayInput(Exception exception, string pathFormat, string path, List<User>? user)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -461,7 +461,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="user">List of user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> CreateUsersWithArrayInputOrDefaultAsync(List<User> user, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> CreateUsersWithArrayInputOrDefaultAsync(List<User>? user = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -480,7 +480,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="user">List of user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> CreateUsersWithArrayInputAsync(List<User> user, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> CreateUsersWithArrayInputAsync(List<User>? user = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -539,7 +539,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatCreateUsersWithListInput(List<User> user);
+        partial void FormatCreateUsersWithListInput(List<User>? user);
 
         /// <summary>
         /// Validates the request parameters
@@ -563,7 +563,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="user"></param>
-        protected virtual void AfterCreateUsersWithListInput(ApiResponse<object> apiResponseLocalVar, List<User> user)
+        protected virtual void AfterCreateUsersWithListInput(ApiResponse<object> apiResponseLocalVar, List<User>? user)
         {
         }
 
@@ -574,7 +574,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="user"></param>
-        protected virtual void OnErrorCreateUsersWithListInput(Exception exception, string pathFormat, string path, List<User> user)
+        protected virtual void OnErrorCreateUsersWithListInput(Exception exception, string pathFormat, string path, List<User>? user)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -585,7 +585,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="user">List of user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> CreateUsersWithListInputOrDefaultAsync(List<User> user, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> CreateUsersWithListInputOrDefaultAsync(List<User>? user = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -604,7 +604,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="user">List of user object</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> CreateUsersWithListInputAsync(List<User> user, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> CreateUsersWithListInputAsync(List<User>? user = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -663,7 +663,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatDeleteUser(ref string username);
+        partial void FormatDeleteUser(ref string? username);
 
         /// <summary>
         /// Validates the request parameters
@@ -687,7 +687,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="username"></param>
-        protected virtual void AfterDeleteUser(ApiResponse<object> apiResponseLocalVar, string username)
+        protected virtual void AfterDeleteUser(ApiResponse<object> apiResponseLocalVar, string? username)
         {
         }
 
@@ -698,7 +698,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="username"></param>
-        protected virtual void OnErrorDeleteUser(Exception exception, string pathFormat, string path, string username)
+        protected virtual void OnErrorDeleteUser(Exception exception, string pathFormat, string path, string? username)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -709,7 +709,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="username">The name that needs to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> DeleteUserOrDefaultAsync(string username, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> DeleteUserOrDefaultAsync(string? username = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -728,7 +728,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="username">The name that needs to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> DeleteUserAsync(string username, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> DeleteUserAsync(string? username = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -774,7 +774,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatGetUserByName(ref string username);
+        partial void FormatGetUserByName(ref string? username);
 
         /// <summary>
         /// Validates the request parameters
@@ -798,7 +798,7 @@ namespace Org.OpenAPITools.Api
         /// </summary>
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="username"></param>
-        protected virtual void AfterGetUserByName(ApiResponse<User> apiResponseLocalVar, string username)
+        protected virtual void AfterGetUserByName(ApiResponse<User> apiResponseLocalVar, string? username)
         {
         }
 
@@ -809,7 +809,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="pathFormat"></param>
         /// <param name="path"></param>
         /// <param name="username"></param>
-        protected virtual void OnErrorGetUserByName(Exception exception, string pathFormat, string path, string username)
+        protected virtual void OnErrorGetUserByName(Exception exception, string pathFormat, string path, string? username)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -820,7 +820,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="username">The name that needs to be fetched. Use user1 for testing.</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="User"/></returns>
-        public async Task<ApiResponse<User>?> GetUserByNameOrDefaultAsync(string username, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<User>?> GetUserByNameOrDefaultAsync(string? username = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -839,7 +839,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="username">The name that needs to be fetched. Use user1 for testing.</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="User"/></returns>
-        public async Task<ApiResponse<User>> GetUserByNameAsync(string username, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<User>> GetUserByNameAsync(string? username = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -895,7 +895,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatLoginUser(ref string username, ref string password);
+        partial void FormatLoginUser(ref string? username, ref string? password);
 
         /// <summary>
         /// Validates the request parameters
@@ -924,7 +924,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="username"></param>
         /// <param name="password"></param>
-        protected virtual void AfterLoginUser(ApiResponse<string> apiResponseLocalVar, string username, string password)
+        protected virtual void AfterLoginUser(ApiResponse<string> apiResponseLocalVar, string? username, string? password)
         {
         }
 
@@ -936,7 +936,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="path"></param>
         /// <param name="username"></param>
         /// <param name="password"></param>
-        protected virtual void OnErrorLoginUser(Exception exception, string pathFormat, string path, string username, string password)
+        protected virtual void OnErrorLoginUser(Exception exception, string pathFormat, string path, string? username, string? password)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -948,7 +948,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="password">The password for login in clear text</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="string"/></returns>
-        public async Task<ApiResponse<string>?> LoginUserOrDefaultAsync(string username, string password, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<string>?> LoginUserOrDefaultAsync(string? username = null, string? password = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -968,7 +968,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="password">The password for login in clear text</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="string"/></returns>
-        public async Task<ApiResponse<string>> LoginUserAsync(string username, string password, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<string>> LoginUserAsync(string? username = null, string? password = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 
@@ -1115,7 +1115,7 @@ namespace Org.OpenAPITools.Api
             }
         }
 
-        partial void FormatUpdateUser(User user, ref string username);
+        partial void FormatUpdateUser(User? user, ref string? username);
 
         /// <summary>
         /// Validates the request parameters
@@ -1144,7 +1144,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="apiResponseLocalVar"></param>
         /// <param name="user"></param>
         /// <param name="username"></param>
-        protected virtual void AfterUpdateUser(ApiResponse<object> apiResponseLocalVar, User user, string username)
+        protected virtual void AfterUpdateUser(ApiResponse<object> apiResponseLocalVar, User? user, string? username)
         {
         }
 
@@ -1156,7 +1156,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="path"></param>
         /// <param name="user"></param>
         /// <param name="username"></param>
-        protected virtual void OnErrorUpdateUser(Exception exception, string pathFormat, string path, User user, string username)
+        protected virtual void OnErrorUpdateUser(Exception exception, string pathFormat, string path, User? user, string? username)
         {
             Logger.LogError(exception, "An error occurred while sending the request to the server.");
         }
@@ -1168,7 +1168,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="username">name that need to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>?> UpdateUserOrDefaultAsync(User user, string username, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>?> UpdateUserOrDefaultAsync(User? user = null, string? username = null, System.Threading.CancellationToken cancellationToken = default)
         {
             try
             {
@@ -1188,7 +1188,7 @@ namespace Org.OpenAPITools.Api
         /// <param name="username">name that need to be deleted</param>
         /// <param name="cancellationToken">Cancellation Token to cancel the request.</param>
         /// <returns><see cref="Task"/>&lt;<see cref="ApiResponse{T}"/>&gt; where T : <see cref="object"/></returns>
-        public async Task<ApiResponse<object>> UpdateUserAsync(User user, string username, System.Threading.CancellationToken cancellationToken = default)
+        public async Task<ApiResponse<object>> UpdateUserAsync(User? user = null, string? username = null, System.Threading.CancellationToken cancellationToken = default)
         {
             UriBuilder uriBuilderLocalVar = new UriBuilder();
 

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Activity.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="activityOutputs">activityOutputs</param>
         [JsonConstructor]
-        public Activity(Dictionary<string, List<ActivityOutputElementRepresentation>> activityOutputs)
+        public Activity(Dictionary<string, List<ActivityOutputElementRepresentation>>? activityOutputs = default)
         {
             ActivityOutputs = activityOutputs;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets ActivityOutputs
         /// </summary>
         [JsonPropertyName("activity_outputs")]
-        public Dictionary<string, List<ActivityOutputElementRepresentation>> ActivityOutputs { get; set; }
+        public Dictionary<string, List<ActivityOutputElementRepresentation>>? ActivityOutputs { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ActivityOutputElementRepresentation.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="prop1">prop1</param>
         /// <param name="prop2">prop2</param>
         [JsonConstructor]
-        public ActivityOutputElementRepresentation(string prop1, Object prop2)
+        public ActivityOutputElementRepresentation(string? prop1 = default, Object? prop2 = default)
         {
             Prop1 = prop1;
             Prop2 = prop2;
@@ -49,13 +49,13 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Prop1
         /// </summary>
         [JsonPropertyName("prop1")]
-        public string Prop1 { get; set; }
+        public string? Prop1 { get; set; }
 
         /// <summary>
         /// Gets or Sets Prop2
         /// </summary>
         [JsonPropertyName("prop2")]
-        public Object Prop2 { get; set; }
+        public Object? Prop2 { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/AdditionalPropertiesClass.cs

@@ -42,7 +42,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="mapWithUndeclaredPropertiesString">mapWithUndeclaredPropertiesString</param>
         /// <param name="anytype1">anytype1</param>
         [JsonConstructor]
-        public AdditionalPropertiesClass(Object emptyMap, Dictionary<string, Dictionary<string, string>> mapOfMapProperty, Dictionary<string, string> mapProperty, Object mapWithUndeclaredPropertiesAnytype1, Object mapWithUndeclaredPropertiesAnytype2, Dictionary<string, Object> mapWithUndeclaredPropertiesAnytype3, Dictionary<string, string> mapWithUndeclaredPropertiesString, Object? anytype1 = default)
+        public AdditionalPropertiesClass(Object? emptyMap = default, Dictionary<string, Dictionary<string, string>>? mapOfMapProperty = default, Dictionary<string, string>? mapProperty = default, Object? mapWithUndeclaredPropertiesAnytype1 = default, Object? mapWithUndeclaredPropertiesAnytype2 = default, Dictionary<string, Object>? mapWithUndeclaredPropertiesAnytype3 = default, Dictionary<string, string>? mapWithUndeclaredPropertiesString = default, Object? anytype1 = default)
         {
             EmptyMap = emptyMap;
             MapOfMapProperty = mapOfMapProperty;
@@ -62,43 +62,43 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <value>an object with no declared properties and no undeclared properties, hence it&#39;s an empty map.</value>
         [JsonPropertyName("empty_map")]
-        public Object EmptyMap { get; set; }
+        public Object? EmptyMap { get; set; }
 
         /// <summary>
         /// Gets or Sets MapOfMapProperty
         /// </summary>
         [JsonPropertyName("map_of_map_property")]
-        public Dictionary<string, Dictionary<string, string>> MapOfMapProperty { get; set; }
+        public Dictionary<string, Dictionary<string, string>>? MapOfMapProperty { get; set; }
 
         /// <summary>
         /// Gets or Sets MapProperty
         /// </summary>
         [JsonPropertyName("map_property")]
-        public Dictionary<string, string> MapProperty { get; set; }
+        public Dictionary<string, string>? MapProperty { get; set; }
 
         /// <summary>
         /// Gets or Sets MapWithUndeclaredPropertiesAnytype1
         /// </summary>
         [JsonPropertyName("map_with_undeclared_properties_anytype_1")]
-        public Object MapWithUndeclaredPropertiesAnytype1 { get; set; }
+        public Object? MapWithUndeclaredPropertiesAnytype1 { get; set; }
 
         /// <summary>
         /// Gets or Sets MapWithUndeclaredPropertiesAnytype2
         /// </summary>
         [JsonPropertyName("map_with_undeclared_properties_anytype_2")]
-        public Object MapWithUndeclaredPropertiesAnytype2 { get; set; }
+        public Object? MapWithUndeclaredPropertiesAnytype2 { get; set; }
 
         /// <summary>
         /// Gets or Sets MapWithUndeclaredPropertiesAnytype3
         /// </summary>
         [JsonPropertyName("map_with_undeclared_properties_anytype_3")]
-        public Dictionary<string, Object> MapWithUndeclaredPropertiesAnytype3 { get; set; }
+        public Dictionary<string, Object>? MapWithUndeclaredPropertiesAnytype3 { get; set; }
 
         /// <summary>
         /// Gets or Sets MapWithUndeclaredPropertiesString
         /// </summary>
         [JsonPropertyName("map_with_undeclared_properties_string")]
-        public Dictionary<string, string> MapWithUndeclaredPropertiesString { get; set; }
+        public Dictionary<string, string>? MapWithUndeclaredPropertiesString { get; set; }
 
         /// <summary>
         /// Gets or Sets Anytype1

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Animal.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="className">className</param>
         /// <param name="color">color (default to &quot;red&quot;)</param>
         [JsonConstructor]
-        public Animal(string className, string color = @"red")
+        public Animal(string? className = default, string? color = @"red")
         {
             ClassName = className;
             Color = color;
@@ -49,13 +49,13 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets ClassName
         /// </summary>
         [JsonPropertyName("className")]
-        public string ClassName { get; set; }
+        public string? ClassName { get; set; }
 
         /// <summary>
         /// Gets or Sets Color
         /// </summary>
         [JsonPropertyName("color")]
-        public string Color { get; set; }
+        public string? Color { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ApiResponse.cs

@@ -37,7 +37,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="message">message</param>
         /// <param name="type">type</param>
         [JsonConstructor]
-        public ApiResponse(int code, string message, string type)
+        public ApiResponse(int code, string? message = default, string? type = default)
         {
             Code = code;
             Message = message;
@@ -57,13 +57,13 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Message
         /// </summary>
         [JsonPropertyName("message")]
-        public string Message { get; set; }
+        public string? Message { get; set; }
 
         /// <summary>
         /// Gets or Sets Type
         /// </summary>
         [JsonPropertyName("type")]
-        public string Type { get; set; }
+        public string? Type { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Apple.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="cultivar">cultivar</param>
         /// <param name="origin">origin</param>
         [JsonConstructor]
-        public Apple(string cultivar, string origin)
+        public Apple(string? cultivar = default, string? origin = default)
         {
             Cultivar = cultivar;
             Origin = origin;
@@ -49,13 +49,13 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Cultivar
         /// </summary>
         [JsonPropertyName("cultivar")]
-        public string Cultivar { get; set; }
+        public string? Cultivar { get; set; }
 
         /// <summary>
         /// Gets or Sets Origin
         /// </summary>
         [JsonPropertyName("origin")]
-        public string Origin { get; set; }
+        public string? Origin { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/AppleReq.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="cultivar">cultivar</param>
         /// <param name="mealy">mealy</param>
         [JsonConstructor]
-        public AppleReq(string cultivar, bool mealy)
+        public AppleReq(string? cultivar = default, bool mealy)
         {
             Cultivar = cultivar;
             Mealy = mealy;
@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Cultivar
         /// </summary>
         [JsonPropertyName("cultivar")]
-        public string Cultivar { get; set; }
+        public string? Cultivar { get; set; }
 
         /// <summary>
         /// Gets or Sets Mealy

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ArrayOfArrayOfNumberOnly.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="arrayArrayNumber">arrayArrayNumber</param>
         [JsonConstructor]
-        public ArrayOfArrayOfNumberOnly(List<List<decimal>> arrayArrayNumber)
+        public ArrayOfArrayOfNumberOnly(List<List<decimal>>? arrayArrayNumber = default)
         {
             ArrayArrayNumber = arrayArrayNumber;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets ArrayArrayNumber
         /// </summary>
         [JsonPropertyName("ArrayArrayNumber")]
-        public List<List<decimal>> ArrayArrayNumber { get; set; }
+        public List<List<decimal>>? ArrayArrayNumber { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ArrayOfNumberOnly.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="arrayNumber">arrayNumber</param>
         [JsonConstructor]
-        public ArrayOfNumberOnly(List<decimal> arrayNumber)
+        public ArrayOfNumberOnly(List<decimal>? arrayNumber = default)
         {
             ArrayNumber = arrayNumber;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets ArrayNumber
         /// </summary>
         [JsonPropertyName("ArrayNumber")]
-        public List<decimal> ArrayNumber { get; set; }
+        public List<decimal>? ArrayNumber { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ArrayTest.cs

@@ -37,7 +37,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="arrayArrayOfModel">arrayArrayOfModel</param>
         /// <param name="arrayOfString">arrayOfString</param>
         [JsonConstructor]
-        public ArrayTest(List<List<long>> arrayArrayOfInteger, List<List<ReadOnlyFirst>> arrayArrayOfModel, List<string> arrayOfString)
+        public ArrayTest(List<List<long>>? arrayArrayOfInteger = default, List<List<ReadOnlyFirst>>? arrayArrayOfModel = default, List<string>? arrayOfString = default)
         {
             ArrayArrayOfInteger = arrayArrayOfInteger;
             ArrayArrayOfModel = arrayArrayOfModel;
@@ -51,19 +51,19 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets ArrayArrayOfInteger
         /// </summary>
         [JsonPropertyName("array_array_of_integer")]
-        public List<List<long>> ArrayArrayOfInteger { get; set; }
+        public List<List<long>>? ArrayArrayOfInteger { get; set; }
 
         /// <summary>
         /// Gets or Sets ArrayArrayOfModel
         /// </summary>
         [JsonPropertyName("array_array_of_model")]
-        public List<List<ReadOnlyFirst>> ArrayArrayOfModel { get; set; }
+        public List<List<ReadOnlyFirst>>? ArrayArrayOfModel { get; set; }
 
         /// <summary>
         /// Gets or Sets ArrayOfString
         /// </summary>
         [JsonPropertyName("array_of_string")]
-        public List<string> ArrayOfString { get; set; }
+        public List<string>? ArrayOfString { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/BasquePig.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="className">className</param>
         [JsonConstructor]
-        public BasquePig(string className)
+        public BasquePig(string? className = default)
         {
             ClassName = className;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets ClassName
         /// </summary>
         [JsonPropertyName("className")]
-        public string ClassName { get; set; }
+        public string? ClassName { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Capitalization.cs

@@ -40,7 +40,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="smallCamel">smallCamel</param>
         /// <param name="smallSnake">smallSnake</param>
         [JsonConstructor]
-        public Capitalization(string aTTNAME, string capitalCamel, string capitalSnake, string sCAETHFlowPoints, string smallCamel, string smallSnake)
+        public Capitalization(string? aTTNAME = default, string? capitalCamel = default, string? capitalSnake = default, string? sCAETHFlowPoints = default, string? smallCamel = default, string? smallSnake = default)
         {
             ATT_NAME = aTTNAME;
             CapitalCamel = capitalCamel;
@@ -58,37 +58,37 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <value>Name of the pet </value>
         [JsonPropertyName("ATT_NAME")]
-        public string ATT_NAME { get; set; }
+        public string? ATT_NAME { get; set; }
 
         /// <summary>
         /// Gets or Sets CapitalCamel
         /// </summary>
         [JsonPropertyName("CapitalCamel")]
-        public string CapitalCamel { get; set; }
+        public string? CapitalCamel { get; set; }
 
         /// <summary>
         /// Gets or Sets CapitalSnake
         /// </summary>
         [JsonPropertyName("Capital_Snake")]
-        public string CapitalSnake { get; set; }
+        public string? CapitalSnake { get; set; }
 
         /// <summary>
         /// Gets or Sets SCAETHFlowPoints
         /// </summary>
         [JsonPropertyName("SCA_ETH_Flow_Points")]
-        public string SCAETHFlowPoints { get; set; }
+        public string? SCAETHFlowPoints { get; set; }
 
         /// <summary>
         /// Gets or Sets SmallCamel
         /// </summary>
         [JsonPropertyName("smallCamel")]
-        public string SmallCamel { get; set; }
+        public string? SmallCamel { get; set; }
 
         /// <summary>
         /// Gets or Sets SmallSnake
         /// </summary>
         [JsonPropertyName("small_Snake")]
-        public string SmallSnake { get; set; }
+        public string? SmallSnake { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Cat.cs

@@ -38,7 +38,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="className">className</param>
         /// <param name="color">color (default to &quot;red&quot;)</param>
         [JsonConstructor]
-        internal Cat(Dictionary<string, int> dictionary, CatAllOf catAllOf, string className, string color = @"red") : base(className, color)
+        internal Cat(Dictionary<string, int> dictionary, CatAllOf catAllOf, string? className = default, string? color = @"red") : base(className, color)
         {
             Dictionary = dictionary;
             CatAllOf = catAllOf;

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Category.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="id">id</param>
         /// <param name="name">name (default to &quot;default-name&quot;)</param>
         [JsonConstructor]
-        public Category(long id, string name = @"default-name")
+        public Category(long id, string? name = @"default-name")
         {
             Id = id;
             Name = name;
@@ -55,7 +55,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Name
         /// </summary>
         [JsonPropertyName("name")]
-        public string Name { get; set; }
+        public string? Name { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ChildCat.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="childCatAllOf"></param>
         /// <param name="petType">petType</param>
         [JsonConstructor]
-        internal ChildCat(ChildCatAllOf childCatAllOf, string petType) : base(petType)
+        internal ChildCat(ChildCatAllOf childCatAllOf, string? petType = default) : base(petType)
         {
             ChildCatAllOf = childCatAllOf;
             OnCreated();

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ChildCatAllOf.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="name">name</param>
         /// <param name="petType">petType (default to PetTypeEnum.ChildCat)</param>
         [JsonConstructor]
-        public ChildCatAllOf(string name, PetTypeEnum petType = PetTypeEnum.ChildCat)
+        public ChildCatAllOf(string? name = default, PetTypeEnum petType = PetTypeEnum.ChildCat)
         {
             Name = name;
             PetType = petType;
@@ -93,7 +93,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Name
         /// </summary>
         [JsonPropertyName("name")]
-        public string Name { get; set; }
+        public string? Name { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ClassModel.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="varClass">varClass</param>
         [JsonConstructor]
-        public ClassModel(string varClass)
+        public ClassModel(string? varClass = default)
         {
             VarClass = varClass;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets VarClass
         /// </summary>
         [JsonPropertyName("_class")]
-        public string VarClass { get; set; }
+        public string? VarClass { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/DanishPig.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="className">className</param>
         [JsonConstructor]
-        public DanishPig(string className)
+        public DanishPig(string? className = default)
         {
             ClassName = className;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets ClassName
         /// </summary>
         [JsonPropertyName("className")]
-        public string ClassName { get; set; }
+        public string? ClassName { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/DeprecatedObject.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="name">name</param>
         [JsonConstructor]
-        public DeprecatedObject(string name)
+        public DeprecatedObject(string? name = default)
         {
             Name = name;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Name
         /// </summary>
         [JsonPropertyName("name")]
-        public string Name { get; set; }
+        public string? Name { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Dog.cs

@@ -37,7 +37,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="className">className</param>
         /// <param name="color">color (default to &quot;red&quot;)</param>
         [JsonConstructor]
-        internal Dog(DogAllOf dogAllOf, string className, string color = @"red") : base(className, color)
+        internal Dog(DogAllOf dogAllOf, string? className = default, string? color = @"red") : base(className, color)
         {
             DogAllOf = dogAllOf;
             OnCreated();

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/DogAllOf.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="breed">breed</param>
         [JsonConstructor]
-        public DogAllOf(string breed)
+        public DogAllOf(string? breed = default)
         {
             Breed = breed;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Breed
         /// </summary>
         [JsonPropertyName("breed")]
-        public string Breed { get; set; }
+        public string? Breed { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Drawing.cs

@@ -38,7 +38,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="shapes">shapes</param>
         /// <param name="nullableShape">nullableShape</param>
         [JsonConstructor]
-        public Drawing(Shape mainShape, ShapeOrNull shapeOrNull, List<Shape> shapes, NullableShape? nullableShape = default) : base()
+        public Drawing(Shape? mainShape = default, ShapeOrNull? shapeOrNull = default, List<Shape>? shapes = default, NullableShape? nullableShape = default) : base()
         {
             MainShape = mainShape;
             ShapeOrNull = shapeOrNull;
@@ -53,19 +53,19 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets MainShape
         /// </summary>
         [JsonPropertyName("mainShape")]
-        public Shape MainShape { get; set; }
+        public Shape? MainShape { get; set; }
 
         /// <summary>
         /// Gets or Sets ShapeOrNull
         /// </summary>
         [JsonPropertyName("shapeOrNull")]
-        public ShapeOrNull ShapeOrNull { get; set; }
+        public ShapeOrNull? ShapeOrNull { get; set; }
 
         /// <summary>
         /// Gets or Sets Shapes
         /// </summary>
         [JsonPropertyName("shapes")]
-        public List<Shape> Shapes { get; set; }
+        public List<Shape>? Shapes { get; set; }
 
         /// <summary>
         /// Gets or Sets NullableShape

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/EnumArrays.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="arrayEnum">arrayEnum</param>
         /// <param name="justSymbol">justSymbol</param>
         [JsonConstructor]
-        public EnumArrays(List<EnumArrays.ArrayEnumEnum> arrayEnum, JustSymbolEnum justSymbol)
+        public EnumArrays(List<EnumArrays.ArrayEnumEnum>? arrayEnum = default, JustSymbolEnum justSymbol)
         {
             ArrayEnum = arrayEnum;
             JustSymbol = justSymbol;
@@ -153,7 +153,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets ArrayEnum
         /// </summary>
         [JsonPropertyName("array_enum")]
-        public List<EnumArrays.ArrayEnumEnum> ArrayEnum { get; set; }
+        public List<EnumArrays.ArrayEnumEnum>? ArrayEnum { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/EnumTest.cs

@@ -43,7 +43,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="outerEnumIntegerDefaultValue">outerEnumIntegerDefaultValue</param>
         /// <param name="outerEnum">outerEnum</param>
         [JsonConstructor]
-        public EnumTest(EnumIntegerEnum enumInteger, EnumIntegerOnlyEnum enumIntegerOnly, EnumNumberEnum enumNumber, EnumStringEnum enumString, EnumStringRequiredEnum enumStringRequired, OuterEnumDefaultValue outerEnumDefaultValue, OuterEnumInteger outerEnumInteger, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, OuterEnum? outerEnum = default)
+        public EnumTest(EnumIntegerEnum enumInteger, EnumIntegerOnlyEnum enumIntegerOnly, EnumNumberEnum enumNumber, EnumStringEnum enumString, EnumStringRequiredEnum enumStringRequired, OuterEnumDefaultValue outerEnumDefaultValue, OuterEnumInteger outerEnumInteger, OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue, OuterEnum outerEnum)
         {
             EnumInteger = enumInteger;
             EnumIntegerOnly = enumIntegerOnly;
@@ -366,7 +366,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets OuterEnum
         /// </summary>
         [JsonPropertyName("outerEnum")]
-        public OuterEnum? OuterEnum { get; set; }
+        public OuterEnum OuterEnum { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties
@@ -488,7 +488,7 @@ namespace Org.OpenAPITools.Model
                             break;
                         case "outerEnum":
                             string outerEnumRawValue = utf8JsonReader.GetString();
-                            outerEnum = OuterEnumConverter.FromStringOrDefault(outerEnumRawValue);
+                            outerEnum = OuterEnumConverter.FromString(outerEnumRawValue);
                             break;
                         default:
                             break;
@@ -520,7 +520,7 @@ namespace Org.OpenAPITools.Model
             if (outerEnumIntegerDefaultValue == null)
                 throw new ArgumentNullException(nameof(outerEnumIntegerDefaultValue), "Property is required for class EnumTest.");
 
-            return new EnumTest(enumInteger.Value, enumIntegerOnly.Value, enumNumber.Value, enumString.Value, enumStringRequired.Value, outerEnumDefaultValue.Value, outerEnumInteger.Value, outerEnumIntegerDefaultValue.Value, outerEnum);
+            return new EnumTest(enumInteger.Value, enumIntegerOnly.Value, enumNumber.Value, enumString.Value, enumStringRequired.Value, outerEnumDefaultValue.Value, outerEnumInteger.Value, outerEnumIntegerDefaultValue.Value, outerEnum.Value);
         }
 
         /// <summary>
@@ -562,9 +562,7 @@ namespace Org.OpenAPITools.Model
                 writer.WriteNumber("outerEnumIntegerDefaultValue", outerEnumIntegerDefaultValueRawValue);
             else
                 writer.WriteNull("outerEnumIntegerDefaultValue");
-            if (enumTest.OuterEnum == null)
+            var outerEnumRawValue = OuterEnumConverter.ToJsonValue(enumTest.OuterEnum);
-                writer.WriteNull("outerEnum");
-            var outerEnumRawValue = OuterEnumConverter.ToJsonValue(enumTest.OuterEnum.Value);
             if (outerEnumRawValue != null)
                 writer.WriteString("outerEnum", outerEnumRawValue);
             else

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/File.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="sourceURI">Test capitalization</param>
         [JsonConstructor]
-        public File(string sourceURI)
+        public File(string? sourceURI = default)
         {
             SourceURI = sourceURI;
             OnCreated();
@@ -48,7 +48,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <value>Test capitalization</value>
         [JsonPropertyName("sourceURI")]
-        public string SourceURI { get; set; }
+        public string? SourceURI { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/FileSchemaTestClass.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="file">file</param>
         /// <param name="files">files</param>
         [JsonConstructor]
-        public FileSchemaTestClass(File file, List<File> files)
+        public FileSchemaTestClass(File? file = default, List<File>? files = default)
         {
             File = file;
             Files = files;
@@ -49,13 +49,13 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets File
         /// </summary>
         [JsonPropertyName("file")]
-        public File File { get; set; }
+        public File? File { get; set; }
 
         /// <summary>
         /// Gets or Sets Files
         /// </summary>
         [JsonPropertyName("files")]
-        public List<File> Files { get; set; }
+        public List<File>? Files { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Foo.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="bar">bar (default to &quot;bar&quot;)</param>
         [JsonConstructor]
-        public Foo(string bar = @"bar")
+        public Foo(string? bar = @"bar")
         {
             Bar = bar;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Bar
         /// </summary>
         [JsonPropertyName("bar")]
-        public string Bar { get; set; }
+        public string? Bar { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/FooGetDefaultResponse.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="varString">varString</param>
         [JsonConstructor]
-        public FooGetDefaultResponse(Foo varString)
+        public FooGetDefaultResponse(Foo? varString = default)
         {
             VarString = varString;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets VarString
         /// </summary>
         [JsonPropertyName("string")]
-        public Foo VarString { get; set; }
+        public Foo? VarString { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/FormatTest.cs

@@ -53,7 +53,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="unsignedLong">unsignedLong</param>
         /// <param name="uuid">uuid</param>
         [JsonConstructor]
-        public FormatTest(System.IO.Stream binary, byte[] varByte, DateTime date, DateTime dateTime, decimal varDecimal, double varDouble, float varFloat, int int32, long int64, int integer, decimal number, string password, string patternWithBackslash, string patternWithDigits, string patternWithDigitsAndDelimiter, string varString, uint unsignedInteger, ulong unsignedLong, Guid uuid)
+        public FormatTest(System.IO.Stream? binary = default, byte[]? varByte = default, DateTime date, DateTime dateTime, decimal varDecimal, double varDouble, float varFloat, int int32, long int64, int integer, decimal number, string? password = default, string? patternWithBackslash = default, string? patternWithDigits = default, string? patternWithDigitsAndDelimiter = default, string? varString = default, uint unsignedInteger, ulong unsignedLong, Guid uuid)
         {
             Binary = binary;
             VarByte = varByte;
@@ -83,13 +83,13 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Binary
         /// </summary>
         [JsonPropertyName("binary")]
-        public System.IO.Stream Binary { get; set; }
+        public System.IO.Stream? Binary { get; set; }
 
         /// <summary>
         /// Gets or Sets VarByte
         /// </summary>
         [JsonPropertyName("byte")]
-        public byte[] VarByte { get; set; }
+        public byte[]? VarByte { get; set; }
 
         /// <summary>
         /// Gets or Sets Date
@@ -151,34 +151,34 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Password
         /// </summary>
         [JsonPropertyName("password")]
-        public string Password { get; set; }
+        public string? Password { get; set; }
 
         /// <summary>
         /// None
         /// </summary>
         /// <value>None</value>
         [JsonPropertyName("pattern_with_backslash")]
-        public string PatternWithBackslash { get; set; }
+        public string? PatternWithBackslash { get; set; }
 
         /// <summary>
         /// A string that is a 10 digit number. Can have leading zeros.
         /// </summary>
         /// <value>A string that is a 10 digit number. Can have leading zeros.</value>
         [JsonPropertyName("pattern_with_digits")]
-        public string PatternWithDigits { get; set; }
+        public string? PatternWithDigits { get; set; }
 
         /// <summary>
         /// A string starting with &#39;image_&#39; (case insensitive) and one to three digits following i.e. Image_01.
         /// </summary>
         /// <value>A string starting with &#39;image_&#39; (case insensitive) and one to three digits following i.e. Image_01.</value>
         [JsonPropertyName("pattern_with_digits_and_delimiter")]
-        public string PatternWithDigitsAndDelimiter { get; set; }
+        public string? PatternWithDigitsAndDelimiter { get; set; }
 
         /// <summary>
         /// Gets or Sets VarString
         /// </summary>
         [JsonPropertyName("string")]
-        public string VarString { get; set; }
+        public string? VarString { get; set; }
 
         /// <summary>
         /// Gets or Sets UnsignedInteger

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Fruit.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="apple?"></param>
         /// <param name="color">color</param>
         [JsonConstructor]
-        public Fruit(Apple? apple, string color)
+        public Fruit(Apple? apple, string? color = default)
         {
             Apple = apple;
             Color = color;
@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="banana"></param>
         /// <param name="color">color</param>
         [JsonConstructor]
-        public Fruit(Banana banana, string color)
+        public Fruit(Banana banana, string? color = default)
         {
             Banana = banana;
             Color = color;
@@ -72,7 +72,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Color
         /// </summary>
         [JsonPropertyName("color")]
-        public string Color { get; set; }
+        public string? Color { get; set; }
 
         /// <summary>
         /// Returns the string presentation of the object

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/GmFruit.cs

@@ -37,7 +37,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="banana"></param>
         /// <param name="color">color</param>
         [JsonConstructor]
-        public GmFruit(Apple? apple, Banana banana, string color)
+        public GmFruit(Apple? apple, Banana banana, string? color = default)
         {
             Apple = Apple;
             Banana = Banana;
@@ -61,7 +61,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Color
         /// </summary>
         [JsonPropertyName("color")]
-        public string Color { get; set; }
+        public string? Color { get; set; }
 
         /// <summary>
         /// Returns the string presentation of the object

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/GrandparentAnimal.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="petType">petType</param>
         [JsonConstructor]
-        public GrandparentAnimal(string petType)
+        public GrandparentAnimal(string? petType = default)
         {
             PetType = petType;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets PetType
         /// </summary>
         [JsonPropertyName("pet_type")]
-        public string PetType { get; set; }
+        public string? PetType { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/HasOnlyReadOnly.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="bar">bar</param>
         /// <param name="foo">foo</param>
         [JsonConstructor]
-        internal HasOnlyReadOnly(string bar, string foo)
+        internal HasOnlyReadOnly(string? bar = default, string? foo = default)
         {
             Bar = bar;
             Foo = foo;
@@ -49,13 +49,13 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Bar
         /// </summary>
         [JsonPropertyName("bar")]
-        public string Bar { get; }
+        public string? Bar { get; }
 
         /// <summary>
         /// Gets or Sets Foo
         /// </summary>
         [JsonPropertyName("foo")]
-        public string Foo { get; }
+        public string? Foo { get; }
 
         /// <summary>
         /// Gets or Sets additional properties
@@ -107,8 +107,12 @@ namespace Org.OpenAPITools.Model
             unchecked // Overflow is fine, just wrap
             {
                 int hashCode = 41;
-                hashCode = (hashCode * 59) + Bar.GetHashCode();
+
-                hashCode = (hashCode * 59) + Foo.GetHashCode();
+                if (Bar != null)
+                    hashCode = (hashCode * 59) + Bar.GetHashCode();
+
+                if (Foo != null)
+                    hashCode = (hashCode * 59) + Foo.GetHashCode();
                 hashCode = (hashCode * 59) + AdditionalProperties.GetHashCode();
 
                 return hashCode;

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/List.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="var123List">var123List</param>
         [JsonConstructor]
-        public List(string var123List)
+        public List(string? var123List = default)
         {
             var123List = var123List;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets var123List
         /// </summary>
         [JsonPropertyName("123-list")]
-        public string var123List { get; set; }
+        public string? var123List { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/LiteralStringClass.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="escapedLiteralString">escapedLiteralString (default to &quot;C:\\Users\\username&quot;)</param>
         /// <param name="unescapedLiteralString">unescapedLiteralString (default to &quot;C:\Users\username&quot;)</param>
         [JsonConstructor]
-        public LiteralStringClass(string escapedLiteralString = @"C:\\Users\\username", string unescapedLiteralString = @"C:\Users\username")
+        public LiteralStringClass(string? escapedLiteralString = @"C:\\Users\\username", string? unescapedLiteralString = @"C:\Users\username")
         {
             EscapedLiteralString = escapedLiteralString;
             UnescapedLiteralString = unescapedLiteralString;
@@ -49,13 +49,13 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets EscapedLiteralString
         /// </summary>
         [JsonPropertyName("escapedLiteralString")]
-        public string EscapedLiteralString { get; set; }
+        public string? EscapedLiteralString { get; set; }
 
         /// <summary>
         /// Gets or Sets UnescapedLiteralString
         /// </summary>
         [JsonPropertyName("unescapedLiteralString")]
-        public string UnescapedLiteralString { get; set; }
+        public string? UnescapedLiteralString { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/MapTest.cs

@@ -38,7 +38,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="mapMapOfString">mapMapOfString</param>
         /// <param name="mapOfEnumString">mapOfEnumString</param>
         [JsonConstructor]
-        public MapTest(Dictionary<string, bool> directMap, Dictionary<string, bool> indirectMap, Dictionary<string, Dictionary<string, string>> mapMapOfString, Dictionary<string, MapTest.InnerEnum> mapOfEnumString)
+        public MapTest(Dictionary<string, bool>? directMap = default, Dictionary<string, bool>? indirectMap = default, Dictionary<string, Dictionary<string, string>>? mapMapOfString = default, Dictionary<string, MapTest.InnerEnum>? mapOfEnumString = default)
         {
             DirectMap = directMap;
             IndirectMap = indirectMap;
@@ -102,25 +102,25 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets DirectMap
         /// </summary>
         [JsonPropertyName("direct_map")]
-        public Dictionary<string, bool> DirectMap { get; set; }
+        public Dictionary<string, bool>? DirectMap { get; set; }
 
         /// <summary>
         /// Gets or Sets IndirectMap
         /// </summary>
         [JsonPropertyName("indirect_map")]
-        public Dictionary<string, bool> IndirectMap { get; set; }
+        public Dictionary<string, bool>? IndirectMap { get; set; }
 
         /// <summary>
         /// Gets or Sets MapMapOfString
         /// </summary>
         [JsonPropertyName("map_map_of_string")]
-        public Dictionary<string, Dictionary<string, string>> MapMapOfString { get; set; }
+        public Dictionary<string, Dictionary<string, string>>? MapMapOfString { get; set; }
 
         /// <summary>
         /// Gets or Sets MapOfEnumString
         /// </summary>
         [JsonPropertyName("map_of_enum_string")]
-        public Dictionary<string, MapTest.InnerEnum> MapOfEnumString { get; set; }
+        public Dictionary<string, MapTest.InnerEnum>? MapOfEnumString { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/MixedPropertiesAndAdditionalPropertiesClass.cs

@@ -38,7 +38,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="uuid">uuid</param>
         /// <param name="uuidWithPattern">uuidWithPattern</param>
         [JsonConstructor]
-        public MixedPropertiesAndAdditionalPropertiesClass(DateTime dateTime, Dictionary<string, Animal> map, Guid uuid, Guid uuidWithPattern)
+        public MixedPropertiesAndAdditionalPropertiesClass(DateTime dateTime, Dictionary<string, Animal>? map = default, Guid uuid, Guid uuidWithPattern)
         {
             DateTime = dateTime;
             Map = map;
@@ -59,7 +59,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets Map
         /// </summary>
         [JsonPropertyName("map")]
-        public Dictionary<string, Animal> Map { get; set; }
+        public Dictionary<string, Animal>? Map { get; set; }
 
         /// <summary>
         /// Gets or Sets Uuid

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/Model200Response.cs

@@ -36,7 +36,7 @@ namespace Org.OpenAPITools.Model
         /// <param name="varClass">varClass</param>
         /// <param name="name">name</param>
         [JsonConstructor]
-        public Model200Response(string varClass, int name)
+        public Model200Response(string? varClass = default, int name)
         {
             VarClass = varClass;
             Name = name;
@@ -49,7 +49,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets VarClass
         /// </summary>
         [JsonPropertyName("class")]
-        public string VarClass { get; set; }
+        public string? VarClass { get; set; }
 
         /// <summary>
         /// Gets or Sets Name

samples/client/petstore/csharp-netcore/OpenAPIClient-generichost-net6.0-nrt/src/Org.OpenAPITools/Model/ModelClient.cs

@@ -35,7 +35,7 @@ namespace Org.OpenAPITools.Model
         /// </summary>
         /// <param name="varClient">varClient</param>
         [JsonConstructor]
-        public ModelClient(string varClient)
+        public ModelClient(string? varClient = default)
         {
             varClient = varClient;
             OnCreated();
@@ -47,7 +47,7 @@ namespace Org.OpenAPITools.Model
         /// Gets or Sets varClient
         /// </summary>
         [JsonPropertyName("client")]
-        public string varClient { get; set; }
+        public string? varClient { get; set; }
 
         /// <summary>
         /// Gets or Sets additional properties