@Override
    public boolean isExpired(final TicketGrantingTicketAwareTicket ticketState) {
        val tgt = ticketState.getTicketGrantingTicket();
        return tgt != null && tgt.isExpired();
    }
This is an {@link AbstractCasExpirationPolicy}
that serves as the root parent for all CAS expiration policies
and exposes a few internal helper methods to children can access
to objects like the request, etc.

@author Misagh Moayyed
@since 4.1
core/cas-server-core-tickets-api/src/main/java/org/apereo/cas/ticket/expiration/AbstractCasExpirationPolicy.java