static getSegment_(id, uri, request) {
    goog.asserts.assert(
        uri.isSegment(),
        'Only segment uri\'s should be given to getSegment');

    /** @type {!shaka.offline.StorageMuxer} */
    const muxer = new shaka.offline.StorageMuxer();

    return shaka.util.AbortableOperation.completed(undefined)
        .chain(() => muxer.init())
        .chain(() => muxer.getCell(uri.mechanism(), uri.cell()))
        .chain((cell) => cell.getSegments([uri.key()]))
        .chain((segments) => {
          const segment = segments[0];

          return {
            uri: uri,
            data: segment.data,
            headers: {},
            originalRequest: request,
          };
        })
        .finally(() => muxer.destroy());
  }
@param {number} id
@param {!shaka.offline.OfflineUri} uri
@param {shaka.extern.Request} request
@return {!shaka.extern.IAbortableOperation.<shaka.extern.Response>}
@private