>Besuretoadd`aria-expanded` to the element `a` and the following `ul`. This attribute explicitly defines the current state of the collapsible element to screen readers and similar assistive technologies. If the collapsible element is closed by default, it should have a value of `aria-expanded="false"`. If you've set the collapsible element's parent `li` element to be open by default using the `active` class, set `aria-expanded="true"`onthecontrolinstead.Thepluginwillautomaticallytogglethisattributebasedonwhetherornotthecollapsibleelementhasbeenopenedorclosed.