angular stomp Sock.js

    import { Injectable } from '@angular/core';
import * as Stomp from 'stompjs/lib/stomp.js';
import * as SockJS from 'sockjs-client';
import {GLOBAL_URL} from '../../shared/constant/url.constant';
import {StartRefresh} from '../../shared/models/start-refresh.model';
import {Subject} from 'rxjs';
@Injectable({
  providedIn: 'root'
})

export class WebSocketAPI {
  webSocketEndPoint: string = GLOBAL_URL + '/socket';
  topic: string = "/message";
  stompClient: any;
  private map = new Subject<StartRefresh>();
  map$ = this.map.asObservable();
  _connect() {
    console.log("Initialize WebSocket Connection");
    let ws = new SockJS(this.webSocketEndPoint);
    this.stompClient = Stomp.over(ws);
    const _this = this;
    _this.stompClient.connect({}, function (frame) {
      _this.stompClient.subscribe(_this.topic, message => {
        _this.onMessageReceived(message.body);
      });
      //_this.stompClient.reconnect_delay = 2000;
    }, this.errorCallBack);
  };

  _disconnect() {
    if (this.stompClient !== null) {
      this.stompClient.disconnect();
    }
    console.log("Disconnected");
  }

  // on error, schedule a reconnection attempt
  errorCallBack(error) {
    console.log("errorCallBack -> " + error)
    setTimeout(() => {
      this._connect();
    }, 5000);
  }

  /**
   * Send message to sever via web socket
   * @param {*} message
   */
  _send(message) {
    console.log("calling logout api via web socket");
    this.stompClient.send("/app/hello", {}, JSON.stringify(message));
  }

  onMessageReceived(startRefresh: StartRefresh) {
    console.log("Message Recieved from Server :: " + startRefresh);
    this.map.next(startRefresh);
  }
}

в консоле браузера пишет это:

[WDS] Warnings while compiling.
warnings @ client:126
client:135 /home/lis/IdeaProjects/application_template/application_template_frontend/src/app/core/websocket/web-socket-api.service.ts depends on 'sockjs-client'. CommonJS or AMD dependencies can cause optimization bailouts.
For more info see: https://angular.io/guide/build#configuring-commonjs-dependencies

depends on 'sockjs-client'. CommonJS or AMD dependencies can cause optimization bailouts.

и с бека соответствено сообщения не приходят