node.listeners = null;
node.listeners = new HashSet();
  public Object clone()  {    try      {        DomNode node = (DomNode) super.clone();                node.parent = null;        node.depth = 0;        node.index = 0;        node.length = 0;        node.first = null;        node.last = null;        node.previous = null;        node.next = null;                node.readonly = false;        node.listeners = null;        node.nListeners = 0;        return node;      }    catch (CloneNotSupportedException x)      {        throw new Error("clone didn't work");      }  }