[dart-dio] Allow dynamic headers and add additional dio parameters (#8191)

* fixes some compile errors due to header params not being of type `String`
* add optional `extra` and `validateStatus` parameters from dio

modules/openapi-generator/src/main/resources/dart-dio/api.mustache

@@ -24,13 +24,17 @@ class {{classname}} {
         {{{dataType}}} {{paramName}},{{/optionalParams}}
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '{{{path}}}'{{#pathParams}}.replaceAll('{' r'{{baseName}}' '}', {{{paramName}}}.toString()){{/pathParams}};
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         {{#headerParams}}
@@ -102,7 +106,9 @@ class {{classname}} {
                             'where': '{{#isKeyInQuery}}query{{/isKeyInQuery}}{{#isKeyInHeader}}header{{/isKeyInHeader}}',{{/isApiKey}}
                         },{{/authMethods}}
                     ],{{/hasAuthMethods}}
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/client/petstore/dart-dio/petstore_client_lib/lib/api/pet_api.dart

@@ -22,13 +22,17 @@ class PetApi {
         Pet body, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -57,7 +61,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -74,13 +80,17 @@ class PetApi {
         String apiKey,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         headerParams[r'api_key'] = apiKey;
@@ -103,7 +113,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -119,13 +131,17 @@ class PetApi {
         BuiltList<String> status, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/findByStatus';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'status'] = status;
@@ -148,7 +164,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -178,13 +196,17 @@ class PetApi {
         BuiltList<String> tags, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/findByTags';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'tags'] = tags;
@@ -207,7 +229,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -237,13 +261,17 @@ class PetApi {
         int petId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -267,7 +295,9 @@ class PetApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -296,13 +326,17 @@ class PetApi {
         Pet body, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -331,7 +365,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -349,13 +385,17 @@ class PetApi {
         String status,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -384,7 +424,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -402,13 +444,17 @@ class PetApi {
         Uint8List file,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -441,7 +487,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/client/petstore/dart-dio/petstore_client_lib/lib/api/store_api.dart

@@ -19,13 +19,17 @@ class StoreApi {
         String orderId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order/{orderId}'.replaceAll('{' r'orderId' '}', orderId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -42,7 +46,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -57,13 +63,17 @@ class StoreApi {
     Future<Response<BuiltMap<String, int>>> getInventory({ 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/inventory';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -87,7 +97,9 @@ class StoreApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -117,13 +129,17 @@ class StoreApi {
         int orderId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order/{orderId}'.replaceAll('{' r'orderId' '}', orderId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -140,7 +156,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -169,13 +187,17 @@ class StoreApi {
         Order body, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -196,7 +218,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/client/petstore/dart-dio/petstore_client_lib/lib/api/user_api.dart

@@ -19,13 +19,17 @@ class UserApi {
         User body, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -46,7 +50,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -62,13 +68,17 @@ class UserApi {
         BuiltList<User> body, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/createWithArray';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -90,7 +100,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -106,13 +118,17 @@ class UserApi {
         BuiltList<User> body, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/createWithList';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -134,7 +150,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -150,13 +168,17 @@ class UserApi {
         String username, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -173,7 +195,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -189,13 +213,17 @@ class UserApi {
         String username, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -212,7 +240,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -242,13 +272,17 @@ class UserApi {
         String password, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/login';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'username'] = username;
@@ -267,7 +301,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -294,13 +330,17 @@ class UserApi {
     Future<Response<void>> logoutUser({ 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/logout';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -317,7 +357,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -334,13 +376,17 @@ class UserApi {
         User body, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -361,7 +407,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib/lib/api/pet_api.dart

@@ -22,13 +22,17 @@ class PetApi {
         Pet pet, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -57,7 +61,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -87,13 +93,17 @@ class PetApi {
         String apiKey,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         headerParams[r'api_key'] = apiKey;
@@ -116,7 +126,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -132,13 +144,17 @@ class PetApi {
         BuiltList<String> status, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/findByStatus';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'status'] = status;
@@ -161,7 +177,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -191,13 +209,17 @@ class PetApi {
         BuiltList<String> tags, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/findByTags';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'tags'] = tags;
@@ -220,7 +242,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -250,13 +274,17 @@ class PetApi {
         int petId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -280,7 +308,9 @@ class PetApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -309,13 +339,17 @@ class PetApi {
         Pet pet, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -344,7 +378,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -375,13 +411,17 @@ class PetApi {
         String status,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -410,7 +450,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -428,13 +470,17 @@ class PetApi {
         Uint8List file,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -467,7 +513,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib/lib/api/store_api.dart

@@ -19,13 +19,17 @@ class StoreApi {
         String orderId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order/{orderId}'.replaceAll('{' r'orderId' '}', orderId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -42,7 +46,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -57,13 +63,17 @@ class StoreApi {
     Future<Response<BuiltMap<String, int>>> getInventory({ 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/inventory';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -87,7 +97,9 @@ class StoreApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -117,13 +129,17 @@ class StoreApi {
         int orderId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order/{orderId}'.replaceAll('{' r'orderId' '}', orderId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -140,7 +156,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -169,13 +187,17 @@ class StoreApi {
         Order order, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -198,7 +220,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib/lib/api/user_api.dart

@@ -19,13 +19,17 @@ class UserApi {
         User user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -55,7 +59,9 @@ class UserApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -71,13 +77,17 @@ class UserApi {
         BuiltList<User> user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/createWithArray';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -108,7 +118,9 @@ class UserApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -124,13 +136,17 @@ class UserApi {
         BuiltList<User> user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/createWithList';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -161,7 +177,9 @@ class UserApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -177,13 +195,17 @@ class UserApi {
         String username, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -207,7 +229,9 @@ class UserApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -223,13 +247,17 @@ class UserApi {
         String username, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -246,7 +274,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -276,13 +306,17 @@ class UserApi {
         String password, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/login';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'username'] = username;
@@ -301,7 +335,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -328,13 +364,17 @@ class UserApi {
     Future<Response<void>> logoutUser({ 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/logout';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -358,7 +398,9 @@ class UserApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -375,13 +417,17 @@ class UserApi {
         User user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -411,7 +457,9 @@ class UserApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/api/another_fake_api.dart

@@ -18,13 +18,17 @@ class AnotherFakeApi {
         ModelClient modelClient, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/another-fake/dummy';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -47,7 +51,9 @@ class AnotherFakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/api/default_api.dart

@@ -17,13 +17,17 @@ class DefaultApi {
     Future<Response<InlineResponseDefault>> fooGet({ 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/foo';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -40,7 +44,9 @@ class DefaultApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/api/fake_api.dart

@@ -25,13 +25,17 @@ class FakeApi {
     Future<Response<HealthCheckResult>> fakeHealthGet({ 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/health';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -48,7 +52,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -79,13 +85,17 @@ class FakeApi {
         String header1,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/http-signature-test';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         headerParams[r'header_1'] = header1;
@@ -116,7 +126,9 @@ class FakeApi {
                             'name': 'http_signature_test',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -132,13 +144,17 @@ class FakeApi {
         bool body,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/outer/boolean';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -161,7 +177,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -189,13 +207,17 @@ class FakeApi {
         OuterComposite outerComposite,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/outer/composite';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -218,7 +240,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -247,13 +271,17 @@ class FakeApi {
         num body,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/outer/number';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -276,7 +304,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -304,13 +334,17 @@ class FakeApi {
         String body,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/outer/string';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -333,7 +367,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -361,13 +397,17 @@ class FakeApi {
         FileSchemaTestClass fileSchemaTestClass, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/body-with-file-schema';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -390,7 +430,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -407,13 +449,17 @@ class FakeApi {
         User user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/body-with-query-params';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'query'] = query;
@@ -437,7 +483,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -453,13 +501,17 @@ class FakeApi {
         ModelClient modelClient, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -482,7 +534,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -524,13 +578,17 @@ class FakeApi {
         String callback,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -571,7 +629,9 @@ class FakeApi {
                             'name': 'http_basic_test',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -594,13 +654,17 @@ class FakeApi {
         String enumFormString,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         headerParams[r'enum_header_string_array'] = enumHeaderStringArray;
@@ -630,7 +694,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -651,13 +717,17 @@ class FakeApi {
         int int64Group,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         headerParams[r'required_boolean_group'] = requiredBooleanGroup;
@@ -685,7 +755,9 @@ class FakeApi {
                             'name': 'bearer_test',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -701,13 +773,17 @@ class FakeApi {
         BuiltMap<String, String> requestBody, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/inline-additionalProperties';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -730,7 +806,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -747,13 +825,17 @@ class FakeApi {
         String param2, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/jsonFormData';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -777,7 +859,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -797,13 +881,17 @@ class FakeApi {
         BuiltList<String> context, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/test-query-paramters';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'pipe'] = pipe;
@@ -825,7 +913,9 @@ class FakeApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/api/fake_classname_tags123_api.dart

@@ -18,13 +18,17 @@ class FakeClassnameTags123Api {
         ModelClient modelClient, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake_classname_test';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -54,7 +58,9 @@ class FakeClassnameTags123Api {
                             'where': 'query',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/api/pet_api.dart

@@ -22,13 +22,17 @@ class PetApi {
         Pet pet, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -57,7 +61,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -74,13 +80,17 @@ class PetApi {
         String apiKey,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         headerParams[r'api_key'] = apiKey;
@@ -103,7 +113,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -119,13 +131,17 @@ class PetApi {
         BuiltList<String> status, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/findByStatus';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'status'] = status;
@@ -148,7 +164,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -178,13 +196,17 @@ class PetApi {
         BuiltList<String> tags, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/findByTags';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'tags'] = tags;
@@ -207,7 +229,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -237,13 +261,17 @@ class PetApi {
         int petId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -267,7 +295,9 @@ class PetApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -296,13 +326,17 @@ class PetApi {
         Pet pet, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -331,7 +365,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -349,13 +385,17 @@ class PetApi {
         String status,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -384,7 +424,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -402,13 +444,17 @@ class PetApi {
         Uint8List file,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/pet/{petId}/uploadImage'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -441,7 +487,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -472,13 +520,17 @@ class PetApi {
         String additionalMetadata,
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/fake/{petId}/uploadImageWithRequiredFile'.replaceAll('{' r'petId' '}', petId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -511,7 +563,9 @@ class PetApi {
                             'name': 'petstore_auth',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/api/store_api.dart

@@ -19,13 +19,17 @@ class StoreApi {
         String orderId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order/{order_id}'.replaceAll('{' r'order_id' '}', orderId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -42,7 +46,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -57,13 +63,17 @@ class StoreApi {
     Future<Response<BuiltMap<String, int>>> getInventory({ 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/inventory';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -87,7 +97,9 @@ class StoreApi {
                             'where': 'header',
                         },
                     ],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -117,13 +129,17 @@ class StoreApi {
         int orderId, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order/{order_id}'.replaceAll('{' r'order_id' '}', orderId.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -140,7 +156,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -169,13 +187,17 @@ class StoreApi {
         Order order, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/store/order';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -198,7 +220,9 @@ class StoreApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,

samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/lib/api/user_api.dart

@@ -19,13 +19,17 @@ class UserApi {
         User user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -48,7 +52,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -64,13 +70,17 @@ class UserApi {
         BuiltList<User> user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/createWithArray';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -94,7 +104,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -110,13 +122,17 @@ class UserApi {
         BuiltList<User> user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/createWithList';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -140,7 +156,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -156,13 +174,17 @@ class UserApi {
         String username, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -179,7 +201,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -195,13 +219,17 @@ class UserApi {
         String username, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -218,7 +246,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -248,13 +278,17 @@ class UserApi {
         String password, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/login';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams[r'username'] = username;
@@ -273,7 +307,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -300,13 +336,17 @@ class UserApi {
     Future<Response<void>> logoutUser({ 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/logout';
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -323,7 +363,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,
@@ -340,13 +382,17 @@ class UserApi {
         User user, { 
         CancelToken cancelToken,
         Map<String, dynamic> headers,
+        Map<String, dynamic> extra,
+        ValidateStatus validateStatus,
         ProgressCallback onSendProgress,
         ProgressCallback onReceiveProgress,
     }) async {
         final String _path = '/user/{username}'.replaceAll('{' r'username' '}', username.toString());
 
         final Map<String, dynamic> queryParams = {};
-        final Map<String, dynamic> headerParams = Map.from(headers ?? {});
+        final Map<String, dynamic> headerParams = {
+            if (headers != null) ...headers,
+        };
         dynamic bodyData;
 
         queryParams.removeWhere((key, value) => value == null);
@@ -369,7 +415,9 @@ class UserApi {
                 headers: headerParams,
                 extra: {
                     'secure': [],
+                    if (extra != null) ...extra,
                 },
+                validateStatus: validateStatus,
                 contentType: contentTypes.isNotEmpty ? contentTypes[0] : 'application/json',
             ),
             cancelToken: cancelToken,