public AbstractEventSource() {
}
@Override
public SubscribeResponse subscribeOp(Subscribe body) {
SubscriptionTicketGrantingResponse databaseResponse = getSubscriptionManagerBackend()
.subscribe(body.getDelivery(), body.getEndTo(), body.getExpires(), body.getFilter(),
body.getFormat());
boolean shouldConvertToDuration;
if (body.getExpires() != null) {
shouldConvertToDuration = DurationAndDateUtil.isDuration(body.getExpires().getValue());