code: protected void maybeBuildAndSetRetryManager(AbstractDraweeController controller) {
      if (!mTapToRetryEnabled) {
        return;
      }
      controller.getRetryManager().setTapToRetryEnabled(mTapToRetryEnabled);
      maybeBuildAndSetGestureDetector(controller);
    }
docs: Installs a retry manager (if specified) to the given controller.