diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
index c5e7ae22505e..ef6e35600998 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/okhttp-gson/ApiClient.mustache
@@ -987,7 +987,7 @@ public class ApiClient {
     }
     {{/dynamicOperations}}
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -1001,6 +1001,7 @@ public class ApiClient {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/ApiClient.java
index 2a6f751bffce..477111bcd94a 100644
--- a/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/echo_api/java/okhttp-gson-user-defined-templates/src/main/java/org/openapitools/client/ApiClient.java
@@ -829,7 +829,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -843,6 +843,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
index 801ad8c88ccd..e97d0c7c8cb9 100644
--- a/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/echo_api/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
@@ -759,7 +759,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -773,6 +773,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/ApiClient.java
index 4513062a964f..92f05cee501f 100644
--- a/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/others/java/okhttp-gson-oneOf-array/src/main/java/org/openapitools/client/ApiClient.java
@@ -733,7 +733,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -747,6 +747,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ApiClient.java
index 5d6e36b9ef8b..a367d6b890c7 100644
--- a/samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/others/java/okhttp-gson-oneOf/src/main/java/org/openapitools/client/ApiClient.java
@@ -733,7 +733,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -747,6 +747,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/ApiClient.java
index e83b0818f8ed..abe4e775969d 100644
--- a/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/others/java/okhttp-gson-streaming/src/main/java/org/openapitools/client/ApiClient.java
@@ -733,7 +733,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -747,6 +747,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/ApiClient.java
index 2a6f751bffce..477111bcd94a 100644
--- a/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-3.1/src/main/java/org/openapitools/client/ApiClient.java
@@ -829,7 +829,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -843,6 +843,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/ApiClient.java
index 5ff8fedbe0c4..d1e0c490c500 100644
--- a/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-awsv4signature/src/main/java/org/openapitools/client/ApiClient.java
@@ -849,7 +849,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -863,6 +863,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/ApiClient.java
index dddbf25cffe7..675020d6dfdc 100644
--- a/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-dynamicOperations/src/main/java/org/openapitools/client/ApiClient.java
@@ -834,7 +834,7 @@ public List<Pair> parameterToPairs(Parameter param, Collection value) {
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -848,6 +848,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/ApiClient.java
index 2a6f751bffce..477111bcd94a 100644
--- a/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-group-parameter/src/main/java/org/openapitools/client/ApiClient.java
@@ -829,7 +829,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -843,6 +843,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/ApiClient.java
index c37f7828c537..f9878faaf404 100644
--- a/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-nullable-required/src/main/java/org/openapitools/client/ApiClient.java
@@ -832,7 +832,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -846,6 +846,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/ApiClient.java
index e136bd9257f0..b771e1be743f 100644
--- a/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-parcelableModel/src/main/java/org/openapitools/client/ApiClient.java
@@ -835,7 +835,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -849,6 +849,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/ApiClient.java
index 2a6f751bffce..477111bcd94a 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger1/src/main/java/org/openapitools/client/ApiClient.java
@@ -829,7 +829,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -843,6 +843,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/ApiClient.java
index 2a6f751bffce..477111bcd94a 100644
--- a/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson-swagger2/src/main/java/org/openapitools/client/ApiClient.java
@@ -829,7 +829,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -843,6 +843,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
index 87e4efc262e4..1dd62fe798d9 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/ApiClient.java
@@ -903,7 +903,7 @@ public List<Pair> parameterToPairs(String collectionFormat, String name, Collect
         return params;
     }
 
-    /**
+   /**
     * Formats the specified free-form query parameters to a list of {@code Pair} objects.
     *
     * @param value The free-form query parameters.
@@ -917,6 +917,7 @@ public List<Pair> freeFormParameterToPairs(Object value) {
             return params;
         }
 
+        @SuppressWarnings("unchecked")
         final Map<String, Object> valuesMap = (Map<String, Object>) value;
 
         for (Map.Entry<String, Object> entry : valuesMap.entrySet()) {