@Override public boolean isExpired(final TicketState ticketState) { if (ticketState == null) { return true; } final ZonedDateTime now = ZonedDateTime.now(ZoneOffset.UTC); final ZonedDateTime expirationTime = ticketState.getLastTimeUsed().plus(this.timeToKillInSeconds, ChronoUnit.SECONDS); return now.isAfter(expirationTime); }