code: function processAfterStateChange(el) {
      const optionValue = el.value;
      const optionIndex = Array.prototype.slice.call(el.parentNode.children).indexOf(el);
      this.setSelectedOption(optionValue);
      emitAndFire(this, 'select-change', {
          index: optionIndex,
          selected: [optionValue],
          el
      });
  }
docs: Common processing after data change via both UI and API
  @param {HTMLElement} el