code: def stop_listener(self):
          '''stop listening for packets'''
          if self.sock is not None:
              self.sock.close()
              self.sock = None
          self.tracks = {f stop_listener(self):
          '''stop listening for packets'''
          if self.sock is not None:
              self.sock.close()
              self.sock = None
          self.tracks = {}
docs: stop listening for packets