call<X>  method 
      
  
Future<E?> 
call<X>( 
    
    
- DynCall<E, X> ? dynCall,
- Map<String, String?> ? callParameters,
- SysProgressListener? onProgress
override
    Implementation
@override
Future<E?> call<X>(DynCall<E, X>? dynCall,
    Map<String, String?>? callParameters, SysProgressListener? onProgress) {
  var requestParameters = buildParameters(callParameters);
  var authorization = buildAuthorization(callParameters);
  var body = buildBody(callParameters, requestParameters);
  var bodyType = buildBodyType(body as String?);
  var maxRetries = errorMaxRetries > 0 ? errorMaxRetries : 0;
  if (maxRetries > 0 && dynCall!.allowRetries) {
    return _callWithRetries(dynCall, callParameters, authorization,
        requestParameters, body, bodyType, maxRetries, [], onProgress);
  } else {
    return _callNoRetries(dynCall, callParameters, authorization,
        requestParameters, body, bodyType, onProgress);
  }
}