public void GivenOwnBankAccount_WhenDeriving_ThenBankAccountRelationMustExist()
        {
            var netherlands = new Countries(this.Session).CountryByIsoCode["NL"];
            var euro        = netherlands.Currency;

            var bank        = new BankBuilder(this.Session).WithCountry(netherlands).WithName("RABOBANK GROEP").WithBic("RABONL2U").Build();
            var bankAccount = new BankAccountBuilder(this.Session).WithBank(bank).WithCurrency(euro).WithIban("NL50RABO0109546784").WithNameOnAccount("Martien").Build();

            this.Session.Commit();

            var builder = new OwnBankAccountBuilder(this.Session);

            builder.Build();

            Assert.True(this.Session.Derive(false).HasErrors);

            this.Session.Rollback();

            builder.WithBankAccount(bankAccount);
            builder.Build();

            Assert.False(this.Session.Derive(false).HasErrors);
        }