public boolean containsKey(String name, boolean global)
public boolean containsKey(QName name, int type)
  public boolean containsKey(String name, boolean global)  {    Iterator i = global ? variables.iterator() : parameters.iterator();    while (i.hasNext())      {        Map ctx = (Map) i.next();        if (ctx.containsKey(name))          {            return true;          }      }    return false;  }