code: function toggleClass(element, value, added) {
    if (!value) {
      return;
    }
  
    if (isNumber(element.length)) {
      forEach(element, function (elem) {
        toggleClass(elem, value, added);
      });
      return;
    } // IE10-11 doesn't support the second parameter of `classList.toggle`
  
  
    if (added) {
      addClass(element, value);
    } else {
      removeClass(element, value);
    }
  }
docs: Add or remove classes from the given element.
  @param {Element} element - The target element.
  @param {string} value - The classes to be toggled.
  @param {boolean} added - Add only.