fix flutter tests

Author: lohanidamodar

tests/languages/flutter/tests.dart

@@ -23,19 +23,19 @@ void main() async {
   print('\nTest Started');
 
   Mock response;
-  response = await foo.get(x: 'string', y: 123, z: ['string in array']);
+  response = await foo.get(y: 123, z: ['string in array']);
   print(response.result);
 
-  response = await foo.post(x: 'string', y: 123, z: ['string in array']);
+  response = await foo.post(y: 123, z: ['string in array']);
   print(response.result);
 
-  response = await foo.put(x: 'string', y: 123, z: ['string in array']);
+  response = await foo.put(y: 123, z: ['string in array']);
   print(response.result);
 
-  response = await foo.patch(x: 'string', y: 123, z: ['string in array']);
+  response = await foo.patch(y: 123, z: ['string in array']);
   print(response.result);
 
-  response = await foo.delete(x: 'string', y: 123, z: ['string in array']);
+  response = await foo.delete(y: 123, z: ['string in array']);
   print(response.result);
 
   // Bar Tests