seekRange() {
    if (this.manifest_ && !this.isRemotePlayback()) {
      // With HLS lazy-loading, there were some situations where the manifest
      // had partially loaded, enough to move onto further load stages, but no
      // segments had been loaded, so the timeline is still unknown.
      // See: https://github.com/shaka-project/shaka-player/pull/4590
      if (!this.fullyLoaded_ &&
          this.manifest_.type == shaka.media.ManifestParser.HLS) {
        return {'start': 0, 'end': 0};
      }
      const timeline = this.manifest_.presentationTimeline;

      return {
        'start': timeline.getSeekRangeStart(),
        'end': timeline.getSeekRangeEnd(),
      };
    }

    // If we have loaded content with src=, we ask the video element for its
    // seekable range.  This covers both plain mp4s and native HLS playbacks.
    if (this.video_ && (this.video_.src || this.isRemotePlayback())) {
      const seekable = this.video_.seekable;
      if (seekable && seekable.length) {
        const playRangeStart =
            this.config_ ? this.config_.playRangeStart : 0;
        const start = Math.max(seekable.start(0), playRangeStart);
        const playRangeEnd =
            this.config_ ? this.config_.playRangeEnd : Infinity;
        const end = Math.min(seekable.end(seekable.length - 1), playRangeEnd);
        return {
          'start': start,
          'end': end,
        };
      }
    }

    return {'start': 0, 'end': 0};
  }
Get the range of time (in seconds) that seeking is allowed. If the player
has not loaded content and the manifest is HLS, this will return a range
from 0 to 0.

@return {{start: number, end: number}}
@export