@Override
  public <T> T getUserData(@NotNull Key<T> key) {
    if (key.equals(TAB_GROUP_ID_KEY)) return (T)myId;
    if (key.equals(TAB_DESCRIPTOR_KEY)) return (T)selectedTab();
    return super.getUserData(key);
  }
@Override
  public <T> T getUserData(@NotNull Key<T> key)