This feature has been deprecated. Use Element#classList.toggle(className)
instead.
Load unpoly-migrate.js
to polyfill deprecated features.
Adds or removes the given class from the given element.
The element for which to add or remove the class.
The class which should be added or removed.
Pass true
to add the class to the element or false
to remove it.
If omitted, the class will be added if missing and removed if present.