constructor(player, item, qualityButton, plugin) {
    super(player, {
      label: item.label,
      selectable: true,
      selected: item.selected || false,
    });
    this.item = item;
    this.qualityButton = qualityButton;
    this.plugin = plugin;
  }
Menu item constructor.

@param {Player} player - vjs player
@param {Object} item - Item object
@param {ConcreteButton} qualityButton - The containing button.
@param {HlsQualitySelectorPlugin} plugin - This plugin instance.