@Override
  public boolean canAcceptDrop(final ChangeListDragBean dragBean) {
    final List<Change> changes = dragBean.getChanges();
    for (Change change : getUserObject().getChanges()) {
      for (Change incomingChange : changes) {
        if (change == incomingChange) return false;
      }
    }

    return true;
  }
@Override
  public boolean canAcceptDrop(final ChangeListDragBean dragBean)