private bool Execute(OpenNewAccountCommand command)
        {
            //this spec is part of Akkatecture
            var spec = new AggregateIsNewSpecification();

            if (spec.IsSatisfiedBy(this))
            {
                var aggregateEvent = new AccountOpenedEvent(command.OpeningBalance);
                Emit(aggregateEvent);
            }

            return(true);
        }
 public void Apply(AccountOpenedEvent aggregateEvent)
 {
     Balance = aggregateEvent.OpeningBalance;
 }