/**
  * @param portType
  * @param operation
  * @param bindingOperation
  */
 private void buildAsync(
     PortType portType, Operation operation, BindingOperation bindingOperation) {
   String operationName = getCustomizedOperationName(operation); // operation.getName();
   if (operationName == null) return;
   Message outputMessage = null;
   if (operation.getOutput() != null)
     outputMessage = operation.getOutput().resolveMessage(wsdlDocument);
   if (outputMessage != null) {
     List<MessagePart> allParts = new ArrayList<MessagePart>(outputMessage.getParts());
     if (options != null && options.additionalHeaders) {
       List<MessagePart> addtionalHeaderParts =
           wsdlModeler.getAdditionHeaderParts(bindingOperation, outputMessage, false);
       allParts.addAll(addtionalHeaderParts);
     }
     if (allParts.size() > 1) build(getOperationName(operationName), allParts);
   }
 }