setTrickPlay(on) {
    const ContentType = shaka.util.ManifestParserUtils.ContentType;

    this.updateSegmentIteratorReverse_();

    const mediaState = this.mediaStates_.get(ContentType.VIDEO);
    if (!mediaState) {
      return;
    }

    const stream = mediaState.stream;
    if (!stream) {
      return;
    }

    shaka.log.debug('setTrickPlay', on);
    if (on) {
      const trickModeVideo = stream.trickModeVideo;
      if (!trickModeVideo) {
        return;  // Can't engage trick play.
      }

      const normalVideo = mediaState.restoreStreamAfterTrickPlay;
      if (normalVideo) {
        return;  // Already in trick play.
      }

      shaka.log.debug('Engaging trick mode stream', trickModeVideo);
      this.switchInternal_(trickModeVideo, /* clearBuffer= */ false,
          /* safeMargin= */ 0, /* force= */ false);

      mediaState.restoreStreamAfterTrickPlay = stream;
    } else {
      const normalVideo = mediaState.restoreStreamAfterTrickPlay;
      if (!normalVideo) {
        return;
      }

      shaka.log.debug('Restoring non-trick-mode stream', normalVideo);
      mediaState.restoreStreamAfterTrickPlay = null;
      this.switchInternal_(normalVideo, /* clearBuffer= */ true,
          /* safeMargin= */ 0, /* force= */ false);
    }
  }
Set trick play on or off.
If trick play is on, related trick play streams will be used when possible.
@param {boolean} on