code: public boolean containsTagHandler(String ns, String localName)
      {
          if (containsNamespace(ns))
          {
              Map<String, TagHandlerFactory> map = _factories.get(ns);
              if (map == null)
              {
                  return false;
              }
              return map.containsKey(localName);
          }
          else
          {
              return false;
          }
      }
docs: /*
  (non-Javadoc)
  
  @see org.apache.myfaces.view.facelets.tag.TagLibrary#containsTagHandler(java.lang.String, java.lang.String)