code: def get_failed_requests(self, results):
          
          data = {member['guid']: member for member in results}
          for request in self.requests:
              if request['guid'] not in data:
                  yield request
docs: Return the requests that failed.
  
          :param results: the results of a membership request check
          :type results: :class:`list`
          :return: the failed requests
          :rtype: generator