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

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