我对Foundation的源代码有些怀疑

Question

这是Foundation的源代码中的Plugin类：

class Plugin {

  constructor(element, options) {
    this._setup(element, options);
    var pluginName = getPluginName(this);
    this.uuid = GetYoDigits(6, pluginName);

    if(!this.$element.attr(`data-${pluginName}`)){ this.$element.attr(`data-${pluginName}`, this.uuid); }
    if(!this.$element.data('zfPlugin')){ this.$element.data('zfPlugin', this); }
    /**
     * Fires when the plugin has initialized.
     * @event Plugin#init
     */
    this.$element.trigger(`init.zf.${pluginName}`);
  }

  destroy() {
    this._destroy();
    var pluginName = getPluginName(this);
    this.$element.removeAttr(`data-${pluginName}`).removeData('zfPlugin')
        /**
         * Fires when the plugin has been destroyed.
         * @event Plugin#destroyed
         */
        .trigger(`destroyed.zf.${pluginName}`);
    for(var prop in this){
      this[prop] = null;//clean up script to prep for garbage collection.
    }
  }
}

我找不到任何绑定为'init.zf.plugin'和'destroyed.zf.plugin'的事件，为什么在这里使用“触发器”？