function syncPlaylist(hours) {
    var durationHourSelectors = document.querySelectorAll('.amplitude-duration-hours[data-amplitude-playlist="' + _config2.default.active_playlist + '"]');

    for (var i = 0; i < durationHourSelectors.length; i++) {
      var songIndex = durationHourSelectors[i].getAttribute("data-amplitude-song-index");

      if (songIndex == null) {
        durationHourSelectors[i].innerHTML = hours;
      }
    }
  }
Syncs the playlist duration hours for the audio.

@param {Integer} hours - The duration hours for the audio.