code: func (as AtomicWebSocketSet) Get(userID uint64) *websocket.Conn {
  	var conn *websocket.Conn
  	as.mutex.Lock()
  	conn = as.sockets[userID]
  	as.mutex.Unlock()
  	runtime.Gosched()
  	return conn
  }
docs: // Get returns a WebSocket connection for a given userID in a thread-safe way.