code: def refresh(self, refresh_done_callback):
          
          self._refresh_callback = refresh_done_callback
          self._fetch_id = 0
          for m in self.mems:
              try:
                  self.mem_read_cb.remove_callback(m.new_data)
                  m.disconnect()
              except Exception as e:
                  logger.info(
                      'Error when removing memory after update: {}'.format(e))
          self.mems = []
  
          self.nbr_of_mems = 0
          self._getting_count = False
  
          logger.debug('Requesting number of memories')
          pk = CRTPPacket()
          pk.set_header(CRTPPort.MEM, CHAN_INFO)
          pk.data = (CMD_INFO_NBR,)
          self.cf.send_packet(pk, expected_reply=(CMD_INFO_NBR,))
docs: Start fetching all the detected memories