code: protected void deliverResponse(T response) {
          synchronized (responseListeners) {
              for (RequestListener.ResponseListener responseListener : responseListeners) {
                  responseListener.onResponse(response);
              }
              if (!this.response.intermediate) {
                  responseListeners.clear();
              }
          }
          if (!this.response.intermediate) {
              synchronized (errorListeners) {
                  errorListeners.clear();
              }
          }
      }
docs: Subclasses must implement this to perform delivery of the parsed
  response to their listeners.  The given response is guaranteed to
  be non-null; responses that fail to parse are not delivered.
  
  @param response The parsed response returned by
  {@link #parseNetworkResponse(NetworkResponse)}