code: def sync(self):
          
          self.send()
          detail_count = summary_count = 0
          while self.responses:
              response = self.responses[0]
              while not response.complete:
                  detail_delta, summary_delta = self.fetch()
                  detail_count += detail_delta
                  summary_count += summary_delta
          return detail_count, summary_count
docs: Send and fetch all outstanding messages.
  
          :return: 2-tuple of number of detail messages and number of summary messages fetched