title: How should I handle the pushsubscriptionchange event?
body: <p><a href="https://www.w3.org/TR/push-api/#the-pushsubscriptionchange-event" rel="nofollow">According to the spec</a>, a <code>pushsubscriptionchange</code> event indicates that "a push subscription has been invalidated, or will soon be invalidated." What are the best practices for handling this event?</p>