diff --git a/modules/openapi-generator/src/main/resources/swift5/APIHelper.mustache b/modules/openapi-generator/src/main/resources/swift5/APIHelper.mustache
index 68d624fb64f..2630944598b 100644
--- a/modules/openapi-generator/src/main/resources/swift5/APIHelper.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/APIHelper.mustache
@@ -7,7 +7,7 @@
 import Foundation
 
 {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} struct APIHelper {
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func rejectNil(_ source: [String:Any?]) -> [String:Any]? {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func rejectNil(_ source: [String: Any?]) -> [String: Any]? {
         let destination = source.reduce(into: [String: Any]()) { (result, item) in
             if let value = item.value {
                 result[item.key] = value
@@ -20,17 +20,17 @@ import Foundation
         return destination
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func rejectNilHeaders(_ source: [String:Any?]) -> [String:String] {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
-            if let collection = item.value as? Array<Any?> {
-                result[item.key] = collection.filter({ $0 != nil }).map{ "\($0!)" }.joined(separator: ",")
+            if let collection = item.value as? [Any?] {
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
         }
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func convertBoolToString(_ source: [String: Any]?) -> [String:Any]? {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func convertBoolToString(_ source: [String: Any]?) -> [String: Any]? {
         guard let source = source else {
             return nil
         }
@@ -46,16 +46,16 @@ import Foundation
     }
 
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func mapValueToPathItem(_ source: Any) -> Any {
-        if let collection = source as? Array<Any?> {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+        if let collection = source as? [Any?] {
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func mapValuesToQueryItems(_ source: [String:Any?]) -> [URLQueryItem]? {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
-            if let collection = item.value as? Array<Any?> {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+            if let collection = item.value as? [Any?] {
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
@@ -69,4 +69,3 @@ import Foundation
         return destination
     }
 }
-
diff --git a/modules/openapi-generator/src/main/resources/swift5/APIs.mustache b/modules/openapi-generator/src/main/resources/swift5/APIs.mustache
index 5429af6973f..fd15cf35a7b 100644
--- a/modules/openapi-generator/src/main/resources/swift5/APIs.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/APIs.mustache
@@ -9,7 +9,7 @@ import Foundation
 {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class {{projectName}}API {
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static var basePath = "{{{basePath}}}"
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static var credential: URLCredential?
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static var customHeaders: [String:String] = [:]{{#useAlamofire}}
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static var customHeaders: [String: String] = [:]{{#useAlamofire}}
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static var requestBuilderFactory: RequestBuilderFactory = AlamofireRequestBuilderFactory(){{/useAlamofire}}{{#useURLSession}}
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static var requestBuilderFactory: RequestBuilderFactory = URLSessionRequestBuilderFactory(){{/useURLSession}}
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static var apiResponseQueue: DispatchQueue = .main
@@ -17,8 +17,8 @@ import Foundation
 
 {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class RequestBuilder<T> {
     var credential: URLCredential?
-    var headers: [String:String]
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} let parameters: [String:Any]?
+    var headers: [String: String]
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} let parameters: [String: Any]?
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} let isBody: Bool
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} let method: String
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} let URLString: String
@@ -26,9 +26,9 @@ import Foundation
     /// Optional block to obtain a reference to the request's progress instance when available.{{#useURLSession}}
     /// With the URLSession http client the request's progress only works on iOS 11.0, macOS 10.13, macCatalyst 13.0, tvOS 11.0, watchOS 4.0.
     /// If you need to get the request's progress in older OS versions, please use Alamofire http client.{{/useURLSession}}
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} var onProgressReady: ((Progress) -> ())?
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} var onProgressReady: ((Progress) -> Void)?
 
-    required {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} init(method: String, URLString: String, parameters: [String:Any]?, isBody: Bool, headers: [String:String] = [:]) {
+    required {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
         self.method = method
         self.URLString = URLString
         self.parameters = parameters
@@ -38,7 +38,7 @@ import Foundation
         addHeaders({{projectName}}API.customHeaders)
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} func addHeaders(_ aHeaders:[String:String]) {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} func addHeaders(_ aHeaders: [String: String]) {
         for (header, value) in aHeaders {
             headers[header] = value
         }
@@ -61,5 +61,5 @@ import Foundation
 
 {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} protocol RequestBuilderFactory {
     func getNonDecodableBuilder<T>() -> RequestBuilder<T>.Type
-    func getBuilder<T:Decodable>() -> RequestBuilder<T>.Type
+    func getBuilder<T: Decodable>() -> RequestBuilder<T>.Type
 }
diff --git a/modules/openapi-generator/src/main/resources/swift5/CodableHelper.mustache b/modules/openapi-generator/src/main/resources/swift5/CodableHelper.mustache
index baad56cca2f..d5b1c1e0a29 100644
--- a/modules/openapi-generator/src/main/resources/swift5/CodableHelper.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/CodableHelper.mustache
@@ -45,4 +45,4 @@ import Foundation
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class func encode<T>(_ value: T) -> Swift.Result<Data, Error> where T: Encodable {
         return Swift.Result { try self.jsonEncoder.encode(value) }
     }
-}
\ No newline at end of file
+}
diff --git a/modules/openapi-generator/src/main/resources/swift5/Configuration.mustache b/modules/openapi-generator/src/main/resources/swift5/Configuration.mustache
index b6e8d28fe4b..47c874815b9 100644
--- a/modules/openapi-generator/src/main/resources/swift5/Configuration.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/Configuration.mustache
@@ -7,10 +7,10 @@
 import Foundation
 
 {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class Configuration {
-	
+
 	// This value is used to configure the date formatter that is used to serialize dates into JSON format. 
 	// You must set it prior to encoding any dates, and it will only be read once. 
 	@available(*, unavailable, message: "To set a different date format, use CodableHelper.dateFormatter instead.")
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static var dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZZZZZ"
-    
-}
\ No newline at end of file
+
+}
diff --git a/modules/openapi-generator/src/main/resources/swift5/Extensions.mustache b/modules/openapi-generator/src/main/resources/swift5/Extensions.mustache
index 311b4bf3b31..1a23697a04b 100644
--- a/modules/openapi-generator/src/main/resources/swift5/Extensions.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/Extensions.mustache
@@ -109,24 +109,24 @@ extension String: CodingKey {
 
 extension KeyedEncodingContainerProtocol {
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} mutating func encodeArray<T>(_ values: [T], forKey key: Self.Key) throws where T : Encodable {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} mutating func encodeArray<T>(_ values: [T], forKey key: Self.Key) throws where T: Encodable {
         var arrayContainer = nestedUnkeyedContainer(forKey: key)
         try arrayContainer.encode(contentsOf: values)
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} mutating func encodeArrayIfPresent<T>(_ values: [T]?, forKey key: Self.Key) throws where T : Encodable {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} mutating func encodeArrayIfPresent<T>(_ values: [T]?, forKey key: Self.Key) throws where T: Encodable {
         if let values = values {
             try encodeArray(values, forKey: key)
         }
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} mutating func encodeMap<T>(_ pairs: [Self.Key: T]) throws where T : Encodable {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} mutating func encodeMap<T>(_ pairs: [Self.Key: T]) throws where T: Encodable {
         for (key, value) in pairs {
             try encode(value, forKey: key)
         }
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} mutating func encodeMapIfPresent<T>(_ pairs: [Self.Key: T]?) throws where T : Encodable {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} mutating func encodeMapIfPresent<T>(_ pairs: [Self.Key: T]?) throws where T: Encodable {
         if let pairs = pairs {
             try encodeMap(pairs)
         }
@@ -136,7 +136,7 @@ extension KeyedEncodingContainerProtocol {
 
 extension KeyedDecodingContainerProtocol {
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func decodeArray<T>(_ type: T.Type, forKey key: Self.Key) throws -> [T] where T : Decodable {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func decodeArray<T>(_ type: T.Type, forKey key: Self.Key) throws -> [T] where T: Decodable {
         var tmpArray = [T]()
 
         var nestedContainer = try nestedUnkeyedContainer(forKey: key)
@@ -148,8 +148,8 @@ extension KeyedDecodingContainerProtocol {
         return tmpArray
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func decodeArrayIfPresent<T>(_ type: T.Type, forKey key: Self.Key) throws -> [T]? where T : Decodable {
-        var tmpArray: [T]? = nil
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func decodeArrayIfPresent<T>(_ type: T.Type, forKey key: Self.Key) throws -> [T]? where T: Decodable {
+        var tmpArray: [T]?
 
         if contains(key) {
             tmpArray = try decodeArray(T.self, forKey: key)
@@ -158,8 +158,8 @@ extension KeyedDecodingContainerProtocol {
         return tmpArray
     }
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func decodeMap<T>(_ type: T.Type, excludedKeys: Set<Self.Key>) throws -> [Self.Key: T] where T : Decodable {
-        var map: [Self.Key : T] = [:]
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func decodeMap<T>(_ type: T.Type, excludedKeys: Set<Self.Key>) throws -> [Self.Key: T] where T: Decodable {
+        var map: [Self.Key: T] = [:]
 
         for key in allKeys {
             if !excludedKeys.contains(key) {
@@ -177,10 +177,10 @@ extension HTTPURLResponse {
     var isStatusCodeSuccessful: Bool {
         return Array(200 ..< 300).contains(statusCode)
     }
-}
+}{{#usePromiseKit}}
 
-{{#usePromiseKit}}extension RequestBuilder {
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func execute() -> Promise<Response<T>>  {
+extension RequestBuilder {
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} func execute() -> Promise<Response<T>> {
         let deferred = Promise<Response<T>>.pending()
         self.execute { result in
             switch result {
diff --git a/modules/openapi-generator/src/main/resources/swift5/JSONDataEncoding.mustache b/modules/openapi-generator/src/main/resources/swift5/JSONDataEncoding.mustache
index 71cdb1da93c..e227058129b 100644
--- a/modules/openapi-generator/src/main/resources/swift5/JSONDataEncoding.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/JSONDataEncoding.mustache
@@ -41,7 +41,7 @@ import Foundation
     }
 
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func encodingParameters(jsonData: Data?) -> [String: Any]? {
-        var returnedParams: [String: Any]? = nil
+        var returnedParams: [String: Any]?
         if let jsonData = jsonData, !jsonData.isEmpty {
             var params: [String: Any] = [:]
             params[jsonDataKey] = jsonData
diff --git a/modules/openapi-generator/src/main/resources/swift5/JSONEncodingHelper.mustache b/modules/openapi-generator/src/main/resources/swift5/JSONEncodingHelper.mustache
index 0191a8fd84a..0eae73e1b39 100644
--- a/modules/openapi-generator/src/main/resources/swift5/JSONEncodingHelper.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/JSONEncodingHelper.mustache
@@ -9,8 +9,8 @@ import Foundation
 
 {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class JSONEncodingHelper {
 
-    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class func encodingParameters<T:Encodable>(forEncodableObject encodableObj: T?) -> [String: Any]? {
-        var params: [String: Any]? = nil
+    {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class func encodingParameters<T: Encodable>(forEncodableObject encodableObj: T?) -> [String: Any]? {
+        var params: [String: Any]?
 
         // Encode the Encodable object
         if let encodableObj = encodableObj {
@@ -27,7 +27,7 @@ import Foundation
     }
 
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class func encodingParameters(forEncodableObject encodableObj: Any?) -> [String: Any]? {
-        var params: [String: Any]? = nil
+        var params: [String: Any]?
 
         if let encodableObj = encodableObj {
             do {
@@ -41,5 +41,5 @@ import Foundation
 
         return params
     }
-    
+
 }
diff --git a/modules/openapi-generator/src/main/resources/swift5/Models.mustache b/modules/openapi-generator/src/main/resources/swift5/Models.mustache
index 595bd9419c2..74ce973b287 100644
--- a/modules/openapi-generator/src/main/resources/swift5/Models.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/Models.mustache
@@ -10,11 +10,11 @@ protocol JSONEncodable {
     func encodeToJSON() -> Any
 }
 
-{{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} enum ErrorResponse : Error {
+{{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} enum ErrorResponse: Error {
     case error(Int, Data?, URLResponse?, Error)
 }
 
-{{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} enum DownloadException : Error {
+{{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} enum DownloadException: Error {
     case responseDataMissing
     case responseFailed
     case requestMissing
@@ -30,7 +30,6 @@ protocol JSONEncodable {
     case generalError(Error)
 }
 
-
 {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}open{{/nonPublicApi}} class Response<T> {
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} let statusCode: Int
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} let header: [String: String]
@@ -44,7 +43,7 @@ protocol JSONEncodable {
 
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} convenience init(response: HTTPURLResponse, body: T?) {
         let rawHeader = response.allHeaderFields
-        var header = [String:String]()
+        var header = [String: String]()
         for (key, value) in rawHeader {
             if let key = key.base as? String, let value = value as? String {
                 header[key] = value
diff --git a/modules/openapi-generator/src/main/resources/swift5/libraries/urlsession/URLSessionImplementations.mustache b/modules/openapi-generator/src/main/resources/swift5/libraries/urlsession/URLSessionImplementations.mustache
index f8c7072b5a5..4582b4bfd54 100644
--- a/modules/openapi-generator/src/main/resources/swift5/libraries/urlsession/URLSessionImplementations.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/libraries/urlsession/URLSessionImplementations.mustache
@@ -44,6 +44,7 @@ private var urlSessionStore = SynchronizedDictionary<String, URLSession>()
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
     
     required {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} init(method: String, URLString: String, parameters: [String : Any]?, isBody: Bool, headers: [String : String] = [:]) {
diff --git a/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/alamofireLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/combineLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/default/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/deprecated/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/deprecated/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/deprecated/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/deprecated/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/deprecated/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/deprecated/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/deprecated/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/deprecated/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 1a1716eb8a3..ddd555e5daa 100644
--- a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ internal struct APIHelper {
     internal static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ internal struct APIHelper {
 
     internal static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ internal struct APIHelper {
     internal static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index 5c97a2b5713..fbbcd7deea0 100644
--- a/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/nonPublicApi/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ internal class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     internal var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required internal init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/objcCompatible/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/promisekitLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/readonlyProperties/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/readonlyProperties/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/readonlyProperties/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/readonlyProperties/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/readonlyProperties/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/readonlyProperties/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/readonlyProperties/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/readonlyProperties/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/resultLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/rxswiftLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {
diff --git a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
index 5b09f955711..1f7f2ffbe17 100644
--- a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
+++ b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/APIHelper.swift
@@ -23,7 +23,7 @@ public struct APIHelper {
     public static func rejectNilHeaders(_ source: [String: Any?]) -> [String: String] {
         return source.reduce(into: [String: String]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                result[item.key] = collection.filter({ $0 != nil }).map { "\($0!)" }.joined(separator: ",")
+                result[item.key] = collection.filter { $0 != nil }.map { "\($0!)" }.joined(separator: ",")
             } else if let value: Any = item.value {
                 result[item.key] = "\(value)"
             }
@@ -47,7 +47,7 @@ public struct APIHelper {
 
     public static func mapValueToPathItem(_ source: Any) -> Any {
         if let collection = source as? [Any?] {
-            return collection.filter({ $0 != nil }).map({"\($0!)"}).joined(separator: ",")
+            return collection.filter { $0 != nil }.map {"\($0!)"}.joined(separator: ",")
         }
         return source
     }
@@ -55,7 +55,7 @@ public struct APIHelper {
     public static func mapValuesToQueryItems(_ source: [String: Any?]) -> [URLQueryItem]? {
         let destination = source.filter({ $0.value != nil}).reduce(into: [URLQueryItem]()) { (result, item) in
             if let collection = item.value as? [Any?] {
-                collection.filter({ $0 != nil }).map({"\($0!)"}).forEach { value in
+                collection.filter { $0 != nil }.map {"\($0!)"}.forEach { value in
                     result.append(URLQueryItem(name: item.key, value: value))
                 }
             } else if let value = item.value {
diff --git a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
index e1bc654b3bc..3a3f7882734 100644
--- a/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
+++ b/samples/client/petstore/swift5/urlsessionLibrary/PetstoreClient/Classes/OpenAPIs/URLSessionImplementations.swift
@@ -44,6 +44,7 @@ open class URLSessionRequestBuilder<T>: RequestBuilder<T> {
      - intercept and handle errors like authorization
      - retry the request.
      */
+    @available(*, deprecated, message: "Please override execute() method to intercept and handle errors like authorization or retry the request. Check the Wiki for more info. https://github.com/OpenAPITools/openapi-generator/wiki/FAQ#how-do-i-implement-bearer-token-authentication-with-urlsession-on-the-swift-api-client")
     public var taskCompletionShouldRetry: ((Data?, URLResponse?, Error?, @escaping (Bool) -> Void) -> Void)?
 
     required public init(method: String, URLString: String, parameters: [String: Any]?, isBody: Bool, headers: [String: String] = [:]) {