code: function calculateSourceAnchor (source, startTime) {
          if (startTime === undefined || isNaN(startTime)) {
            return source;
          }
  
          if (windowType === WindowTypes.STATIC) {
            return startTime === 0 ? source : source + '#t=' + parseInt(startTime);
          }
  
          if (windowType === WindowTypes.SLIDING) {
            return startTime === 0 ? source : source + '#r=' + parseInt(startTime);
          }
  
          if (windowType === WindowTypes.GROWING) {
            var windowStartTimeSeconds = (timeData.windowStartTime / 1000);
            var srcWithTimeAnchor = source + '#t=';
  
            startTime = parseInt(startTime);
            return startTime === 0 ? srcWithTimeAnchor + (windowStartTimeSeconds + 1) : srcWithTimeAnchor + (windowStartTimeSeconds + startTime);
          }
        }
docs: Calculates a source url with anchor tags for playback within dashjs
  
  Anchor tags applied to the MPD source for playback:
  
  #r - relative to the start of the first period defined in the DASH manifest
  #t - time since the beginning of the first period defined in the DASH manifest
  @param {String} source
  @param {Number} startTime