text: (function () {
    if (
      typeof window.Element === "undefined" ||
      "classList" in document.documentElement
    ) {
      return;
    }
  
    var prototype = Array.prototype,
      push = prototype.push,
      splice = prototype.splice,
      join = prototype.join;
  
    function DOMTokenList(el) {
      this.el = el;
      // The className needs to be trimmed and split on whitespace
      // to retrieve a list of classes.
      var classes = el.className.replace(/^\s+|\s+$/g, "").split(/\s+/);
      for (var i = 0; i < classes.length; i++) {
        push.call(this, classes[i]);
      }
    }
  
    DOMTokenList.prototype = {
      add: function (token) {
        if (this.contains(token)) return;
        push.call(this, token);
        this.el.className = this.toString();
      },
      contains: function (token) {
        return this.el.className.indexOf(token) != -1;
      },
      item: function (index) {
        return this[index] || null;
      },
      remove: function (token) {
        if (!this.contains(token)) return;
        for (var i = 0; i < this.length; i++) {
          if (this[i] == token) break;
        }
        splice.call(this, i, 1);
        this.el.className = this.toString();
      },
      toString: function () {
        return join.call(this, " ");
      },
      toggle: function (token) {
        if (!this.contains(token)) {
          this.add(token);
        } else {
          this.remove(token);
        }
  
        return this.contains(token);
      },
    };
  
    window.DOMTokenList = DOMTokenList;
  
    function defineElementGetter(obj, prop, getter) {
      if (Object.defineProperty) {
        Object.defineProperty(obj, prop, {
          get: getter,
        });
      } else {
        obj.__defineGetter__(prop, getter);
      }
    }
  
    defineElementGetter(HTMLElement.prototype, "classList", function () {
      return new DOMTokenList(this);
    });
  })();
  