docs: def add(self, client):
          """Add a client to the penalty box."""
          if client.pool_id in self._client_ids:
              log.info("%r is already in the penalty box. Ignoring.", client)
              return
          release = time.time() + self._min_wait
          heapq.heappush(self._clients, (release, (client, self._min_wait)))
          self._client_ids.add(client.pool_id)