default ZonedDateTime toMaximumExpirationTime(final Ticket ticketState) {
        return null;
    }
Gets maximum expiration time for this ticket.
The ticket will expire at the calculated time.

@param ticketState the ticket state
@return the maximum expiration time
api/cas-server-core-api-ticket/src/main/java/org/apereo/cas/ticket/ExpirationPolicy.java