text: function RingToneService() {
      var _this = this;
      var MAX_VOLUME = 1;
      _this.loadRingTone = function (url, notificationToneOption) {
          var data = {
              src: [url],
              loop: notificationToneOption.loop,
              html5: true,
          };
          data.volume =
              notificationToneOption && notificationToneOption.volume != null
                  ? notificationToneOption.volume
                  : MAX_VOLUME;
          return new Howl(data);
      };
      _this.loadChatPopupTone = function (url, greetingMsgVolumeOption) {
          var data = {
              src: [url],
              html5: true,
          };
          data.volume =
              greetingMsgVolumeOption && greetingMsgVolumeOption.volume != null
                  ? greetingMsgVolumeOption.volume
                  : MAX_VOLUME;
          return new Howl(data);
      };
  }
  