docs: protected void setKeyEvent(KeyEvent keyEvent) {
          if (gvrCursorController instanceof GVRExternalCursorController) {
              GVRExternalCursorController controller = (GVRExternalCursorController)
                      gvrCursorController;
              controller.setKeyEvent(keyEvent);
          } else {
              throw new UnsupportedOperationException("setKeyEvent not supported");
          }
      }