docs: public final void addComponent(String namespace, String name, String componentType, String rendererType, 
                                        Class<? extends TagHandler> handlerType)
      {
          Map<String, TagHandlerFactory> map = _factories.get(namespace);
          if (map == null)
          {
              map = new HashMap<String, TagHandlerFactory>();
              _factories.put(namespace, map);
          }
          map.put(name, new UserComponentHandlerFactory(componentType, rendererType, handlerType));
      }