code: @SuppressWarnings("synthetic-access")
      public void executeRpc(RequestBuilder requestBuilder) {
  
          final RequestCallback callback = requestBuilder.getCallback();
          RequestCallback callbackWrapper = new RequestCallback() {
  
              public void onError(com.google.gwt.http.client.Request request, Throwable exception) {
  
                  m_requestCounter.decrement();
                  callback.onError(request, exception);
              }
  
              public void onResponseReceived(
                  com.google.gwt.http.client.Request request,
                  com.google.gwt.http.client.Response response) {
  
                  m_requestCounter.decrement();
                  callback.onResponseReceived(request, response);
              }
          };
          requestBuilder.setCallback(callbackWrapper);
          m_requestCounter.increment();
          try {
              requestBuilder.send();
          } catch (Exception e) {
              m_requestCounter.decrement();
          }
      }
docs: Executes the RPC call.<p>
  
  @param requestBuilder the request builder returned by the service interface