code: def fetch(self):
          
          if self._newflg:
              self._newflg = False
              temp_dtgram = copy.deepcopy(self._dtgram)
              for (bufid, buffer) in self._buffer.items():
                  temp_dtgram += self.submit(buffer, bufid=bufid)
              return tuple(temp_dtgram)
          return tuple(self._dtgram)
docs: Fetch datagram.