constructor(options) {
    /** @type {string} */
    this.title;

    /** @type {string} */
    this.artist;

    /** @type {!Object} */
    this.artwork;
  }
@fileoverview Externs for MediaSession based on
{@link https://bit.ly/2Id3dGD Editor's Draft, 12 January 2017}

@externs