public void AutoTestCase_Balance_TestAbs() { Amount a1 = new Amount("0.00"); Amount a2 = new Amount("$ 123"); Amount a3 = new Amount("EUR 456"); Balance b0 = new Balance(); Balance b1 = new Balance(); Balance b2 = new Balance(); b1 += a1; b1 += a2; b1 += a3; b2 += -a1; b2 += -a2; b2 += -a3; Assert.Equal(b0.Abs(), b0); Assert.Equal(b2.Abs(), b1.Abs()); Assert.True(b0.Valid()); Assert.True(b1.Valid()); Assert.True(b2.Valid()); }