code: def handle(self, body, signature):
          
          events = self.parser.parse(body, signature)
  
          for event in events:
              func = None
              key = None
  
              if isinstance(event, MessageEvent):
                  key = self.__get_handler_key(
                      event.__class__, event.message.__class__)
                  func = self._handlers.get(key, None)
  
              if func is None:
                  key = self.__get_handler_key(event.__class__)
                  func = self._handlers.get(key, None)
  
              if func is None:
                  func = self._default
  
              if func is None:
                  LOGGER.info('No handler of ' + key + ' and no default handler')
              else:
                  args_count = self.__get_args_count(func)
                  if args_count == 0:
                      func()
                  else:
                      func(event)
docs: Handle webhook.
  
          :param str body: Webhook request body (as text)
          :param str signature: X-Line-Signature value (as text)