notifySegmentsForStreams_(streams) {
    const references = [];
    for (const stream of streams) {
      if (!stream.segmentIndex) {
        // The stream was closed since the list of streams was built.
        continue;
      }
      stream.segmentIndex.forEachTopLevelReference((reference) => {
        references.push(reference);
      });
    }
    this.presentationTimeline_.notifySegments(references);
  }
@param {!Array<!shaka.extern.Stream>} streams
@private