protected override void ExecuteInContext(IUnitOfWorkContext context, AddInvoiceItem command)
{
ITaxRepository taxRepo = NcqrsEnvironment.Get <ITaxRepository>();
Tax tax = taxRepo.FindByCode(command.TaxCode, command.OwnerId);
Invoice invoice = context.GetById <Invoice>(command.InvoiceId, command.KnownVersion);
invoice.AddInvoiceItem(command.ItemId, command.Description, command.Quantity, command.Price, command.DiscountInPercent, tax, command.OwnerId, command.UserName);
context.Accept();
}