code: function(trackIds, options, callback) {
      // In case someone is using a version where options parameter did not exist.
      var actualCallback, actualOptions;
      if (typeof options === 'function' && !callback) {
        actualCallback = options;
        actualOptions = {};
      } else {
        actualCallback = callback;
        actualOptions = options;
      }
  
      return WebApiRequest.builder(this.getAccessToken())
        .withPath('/v1/tracks')
        .withQueryParameters(
          {
            ids: trackIds.join(',')
          },
          actualOptions
        )
        .build()
        .execute(HttpManager.get, actualCallback);
    }
docs: Look up several tracks.
  @param {string[]} trackIds The IDs of the artists.
  @param {Object} [options] The possible options, currently only market.
  @param {requestCallback} [callback] Optional callback method to be called instead of the promise.
  @example getArtists(['0oSGxfWSnnOXhD2fKuz2Gy', '3dBVyJ7JuOMt4GE9607Qin']).then(...)
  @returns {Promise|undefined} A promise that if successful, returns an object containing information
  about the artists. Not returned if a callback is given.