docs: @Override
      public void notifyHangupListeners(Integer cause, String causeText)
      {
          this._isLive = false;
          if (this.hangupListener != null)
          {
              this.hangupListener.channelHangup(this, cause, causeText);
          }
          else
          {
              logger.warn("Hangup listener is null");
          }
      }