code: def connection_lost(self, exc):
          
          if exc:
              log.error("{:d} connection_lost {}", id(self), exc)
          else:
              log.info("{:d} connection_lost", id(self))
docs: (asyncio.Protocol member)
  
          Called upon when a socket closes.
          This class simply logs the disconnection
  
          Args:
              exc (Exception or None): Error if connection closed
                  unexpectedly, None if closed cleanly.