If `requestId` does not exist in `this.requests`, but exists in `this.ackRequests`: https://github.com/socketio/socket.io-redis-adapter/blob/cdb55353f83c78cabe9788683e4dd93ac4cd50c9/lib/index.ts#L529 L537 will have an exception: https://github.com/socketio/socket.io-redis-adapter/blob/cdb55353f83c78cabe9788683e4dd93ac4cd50c9/lib/index.ts#L537