code: function (cls, state) {
          var curState = this.contains(cls);
  
          if (curState !== state) {
            if (curState) {
              this.remove(cls);
            } else {
              this.add(cls);
            }
  
            this._change();
          }
  
          return this;
        }
docs: Toggles a class in the class list.
  
  @method toggle
  @param {String} cls Class to be added/removed.
  @param {Boolean} state Optional state if it should be added/removed.
  @return {tinymce.ui.ClassList} Current class list instance.