Function toggleClass

third_party/js/qunit/qunit.js:6490–6496

(elem, name, force)

      }
    }
    function toggleClass(elem, name, force) {
      if (force || typeof force === 'undefined' && !hasClass(elem, name)) {
        addClass(elem, name);
      } else {
        removeClass(elem, name);
      }
    }
    function removeClass(elem, name) {
      var set = ' ' + elem.className + ' ';