static getTracks_(manifest) {
    const StreamUtils = shaka.util.StreamUtils;

    const tracks = [];

    const variants = StreamUtils.getPlayableVariants(manifest.variants);
    for (const variant of variants) {
      tracks.push(StreamUtils.variantToTrack(variant));
    }

    const textStreams = manifest.textStreams;
    for (const stream of textStreams) {
      tracks.push(StreamUtils.textStreamToTrack(stream));
    }

    return tracks;
  }
Gets track representations of all playable variants and all text streams.

@param {shaka.extern.Manifest} manifest
@return {!Array<shaka.extern.Track>}
@private