code: function connect () {
    // connection
    if (!alreadyConnectedOnce) {
      if (connectedPromise === null) connection = createConnection()
      var url = AppConfig.apiUrl + 'websocket/chat'
      if (accessToken) {
        token = accessToken
        url += '?access_token=' + accessToken
      }
      socket = new SockJS(url)
      stompClient = webstomp.over(socket)
      // stompClient.debug = null
      console.tron.log(`Connecting to ${url}`)
      var headers = {}
      stompClient.connect(headers, onConnect, onError)
      alreadyConnectedOnce = true
    }
  }
docs: methods for connecting/disconnecting