code: public void init( HandlerConfig handlerConfig, Handler previousHandler, ServletContext servletContext )
      {
          _servletContext = servletContext;
          _previousHandler = previousHandler;
          _config = handlerConfig;
      }
docs: Initialize.
  
  @param handlerConfig the configuration object for this Handler.
  @param previousHandler the previously-registered Handler, which this one can adapt.
  @param servletContext the ServletContext for the webapp that is creating this object.