code: private void postConnectError(final ConnectCompletionListener completionListener, final String errorMessage) {
          new Handler(Looper.getMainLooper()).post(new Runnable() {
              @Override
              public void run() {
                  if (null != completionListener) {
                      completionListener.onError(errorMessage);
                  }
              }
          });
      }
docs: A convenience method for posting errors to a ConnectCompletionListener
  
  @param completionListener  The listener to notify
  @param errorMessage        The human-readable error message that occurred