code: def on_close(self) -> None:
          
          logger.info('WebSocket CLOSED')
          if self in connections:
              # Remove this connection from connection-list
              connections.remove(self)
          # close if auto_shutdown is enabled and there is no more connection
          if config.auto_shutdown and not is_connected():
              asyncio.ensure_future(self.terminate())
docs: Execute when connection closed.