public SimpleMessageAggregate(SimpleMessageId userId, DateTimeOffset timestamp)
        {
            var evnt = new SimpleMessageCreated(userId, timestamp);

            Apply(evnt);
        }
 public void When(SimpleMessageCreated @event)
 {
     this.Id        = @event.Id;
     this.Timestamp = @event.Timestamp;
 }
 public void Handle(SimpleMessageCreated @event)
 {
     State.LastModificationDate = @event.Timestamp;
 }