How to use the @clappr/core.Events.CONTAINER_STATE_BUFFERING function in @clappr/core

bindEvents() {
    this.listenTo(this.container, Events.CONTAINER_BITRATE, this.onBitrate)
    this.listenTo(this.container, Events.CONTAINER_STOP, this.stopReporting)
    this.listenTo(this.container, Events.CONTAINER_ENDED, this.stopReporting)
    this.listenToOnce(this.container.playback, Events.PLAYBACK_PLAY_INTENT, this.startTimers)
    this.listenToOnce(this.container, Events.CONTAINER_PLAY, this.onFirstPlaying)
    this.listenTo(this.container, Events.CONTAINER_PLAY, this.onPlay)
    this.listenTo(this.container, Events.CONTAINER_PAUSE, this.onPause)
    this.listenToOnce(this.container, Events.CONTAINER_STATE_BUFFERING, this.onBuffering)
    this.listenTo(this.container, Events.CONTAINER_SEEK, this.onSeek)
    this.listenTo(this.container, Events.CONTAINER_ERROR, () => this._inc('error'))
    this.listenTo(this.container, Events.CONTAINER_FULLSCREEN, () => this._inc('fullscreen'))
    this.listenTo(this.container, Events.CONTAINER_PLAYBACKDVRSTATECHANGED, (dvrInUse) => {dvrInUse && this._inc('dvrUsage')})
    this.listenTo(this.container.playback, Events.PLAYBACK_PROGRESS, this.onProgress)
    this.listenTo(this.container.playback, Events.PLAYBACK_TIMEUPDATE, this.onTimeUpdate)
  }