@ApiStatus.Internal
  public void setCancelOnMouseOutCallback(@Nullable MouseChecker checker) {
    myCancelOnMouseOutCallback = checker;
    if (checker != null && myMouseOutCanceller == null) {
      installMouseOutCanceller();
    }
    else if (checker == null && myMouseOutCanceller != null && !myCancelOnWindow) {
      removeMouseOutCanceller();
    }
  }
@ApiStatus.Internal
  public void setCancelOnMouseOutCallback(@Nullable MouseChecker checker)