public void PostAmount()
{
var account = _debitAccount;
var amount = new Amount(account, EntryType.Debit, 10M);
amount.Post();
Assert.That(account.Balance, Is.EqualTo(10M));
amount = new Amount(account, EntryType.Credit, 10M);
amount.Post();
Assert.That(account.Balance, Is.EqualTo(0M));
}