public void execute_throws_validation_exception_on_missing_severity(
            Envelope<Ticket> ticket,
            Mock<ICommand<Ticket>> inner)
        {
            ticket.Item.Severity = null;
            var sut = new TicketValidator(inner.Object);

            sut.Invoking(s => s.Execute(ticket)).ShouldThrow<ValidationException>();
        }
        public void execute_throws_validation_exception_on_description_bigger_than_500_chars(
            Envelope<Ticket> ticket,
            Mock<ICommand<Ticket>> inner)
        {
            ticket.Item.Description = new string('b', 501);
            var sut = new TicketValidator(inner.Object);

            sut.Invoking(s => s.Execute(ticket)).ShouldThrow<ValidationException>();
        }