function toggleCssProps(manager, add) {
  var element = manager.element;

  if (!element.style) {
    return;
  }
  var prop = void 0;
  each(manager.options.cssProps, function (value, name) {
    prop = prefixed(element.style, name);
    if (add) {
      manager.oldCssProps[prop] = element.style[prop];
      element.style[prop] = value;
    } else {
      element.style[prop] = manager.oldCssProps[prop] || '';
    }
  });
  if (!add) {
    manager.oldCssProps = {};
  }
}
@private
destroy the manager and unbinds all events
it doesn't unbind dom events, that is the user own responsibility