code: def add_request_handler(self, request_handler):
          # type: (AbstractRequestHandler) -> None
          
          if request_handler is None:
              raise RuntimeConfigException(
                  "Valid Request Handler instance to be provided")
  
          if not isinstance(request_handler, AbstractRequestHandler):
              raise RuntimeConfigException(
                  "Input should be a RequestHandler instance")
  
          self.request_handler_chains.append(GenericRequestHandlerChain(
              request_handler=request_handler))
docs: Register input to the request handlers list.
  
          :param request_handler: Request Handler instance to be
              registered.
          :type request_handler: AbstractRequestHandler
          :return: None