parseIFrames_(iFrameTags) {
    // Create iFrame stream for each iFrame tag.
    const iFrameStreams = iFrameTags.map((tag) => {
      const streamInfo = this.createStreamInfoFromIframeTag_(tag);
      const ContentType = shaka.util.ManifestParserUtils.ContentType;
      if (streamInfo.stream.type !== ContentType.VIDEO) {
        return null;
      }
      return streamInfo.stream;
    });

    // Filter mjpg iFrames
    return iFrameStreams.filter((s) => s);
  }
@param {!Array<!shaka.hls.Tag>} iFrameTags from the playlist.
@return {!Array<!shaka.extern.Stream>}
@private