Fix empty model test

Author: diastremskii

modules/openapi-generator/src/test/java/org/openapitools/codegen/kotlin/KotlinClientCodegenModelTest.java

@@ -43,7 +43,7 @@
 import java.util.Map;
 
 import static org.openapitools.codegen.CodegenConstants.*;
-import static org.openapitools.codegen.TestUtils.assertFileContains;
+import static org.openapitools.codegen.languages.KotlinClientCodegen.GENERATE_ONEOF_ANYOF_WRAPPERS;
 
 @SuppressWarnings("static-method")
 public class KotlinClientCodegenModelTest {
@@ -502,7 +502,7 @@ private void givenSchemaObjectPropertyNameContainsDollarSignWhenGenerateThenDoll
 //        properties.put(CodegenConstants.LIBRARY, ClientLibrary.JVM_KTOR);
         properties.put(CodegenConstants.ENUM_PROPERTY_NAMING, CodegenConstants.ENUM_PROPERTY_NAMING_TYPE.UPPERCASE.toString());
         properties.put(SERIALIZATION_LIBRARY, KotlinClientCodegen.SERIALIZATION_LIBRARY_TYPE.gson.toString());
-        properties.put(KotlinClientCodegen.GENERATE_ONEOF_ANYOF_WRAPPERS, true);
+        properties.put(GENERATE_ONEOF_ANYOF_WRAPPERS, true);
         properties.put(API_PACKAGE, "com.toasttab.service.scim.api");
         properties.put(MODEL_PACKAGE, "com.toasttab.service.scim.models");
         properties.put(PACKAGE_NAME, "com.toasttab.service.scim");
@@ -661,6 +661,7 @@ public void emptyModelKotlinxSerializationTest() throws IOException {
                 .setGeneratorName("kotlin")
                 .setAdditionalProperties(new HashMap<>() {{
                     put(CodegenConstants.MODEL_PACKAGE, "model");
+                    put(GENERATE_ONEOF_ANYOF_WRAPPERS, false);
                     put(SERIALIZATION_LIBRARY, "kotlinx_serialization");
                 }})
                 .setInputSpec("src/test/resources/3_0/kotlin/empty-model.yaml")