code: public void clearDereferencedListeners() {
          if (uiThreadRunner.isOnUiThread()) {
              graph.clearDereferencedListeners();
          } else {
              uiThreadRunner.post(new Runnable() {
                  @Override
                  public void run() {
                      graph.clearDereferencedListeners();
                  }
              });
          }
      }
docs: Clear {@link Provider.DereferenceListener}s which will be called when the last cached
  instance of an injected contract is freed.