function createSegmentDB(startTime, endTime, dataKey, mimeType, codecs) {
    /** @type {shaka.extern.SegmentDB} */
    const segment = {
      startTime,
      endTime,
      dataKey,
      initSegmentKey: null,
      appendWindowStart: 0,
      appendWindowEnd: Infinity,
      timestampOffset: 0,
      tilesLayout: '',
      mimeType,
      codecs,
      thumbnailSprite: null,
    };

    return segment;
  }
@param {number} startTime
@param {number} endTime
@param {number} dataKey
@param {string} mimeType
@param {string} codecs
@return {shaka.extern.SegmentDB}