function sync() {
    var volumeSliders = document.getElementsByClassName("amplitude-volume-slider");

    /*
    Iterates over all of the volume sliders for the song, setting the value
    to the config value.
    */
    for (var i = 0; i < volumeSliders.length; i++) {
      volumeSliders[i].value = _config2.default.audio.volume * 100;
    }
  }
Visually syncs the volume sliders so they are all the same if there
are more than one.

@access public