@Override
  public Element filter(Object content) {
    if (content instanceof Element) {
      Element el = (Element)content;
      if (name == null) {
        if (namespace == null) {
          return el;
        }
        return namespace.equals(el.getNamespace()) ? el : null;
      }
      if (!name.equals(el.getName())) {
        return null;
      }
      if (namespace == null) {
        return el;
      }
      return namespace.equals(el.getNamespace()) ? el : null;
    }
    return null;
  }
@Override
  public Element filter(Object content)