public void TestInvert()
{
UnitCartesian Cartesian3 = new UnitCartesian(2.0, 3.0, 6.0);
UnitCartesian inverted = Cartesian3.Invert();
Assert.AreEqual(-2.0 / 7.0, inverted.X);
Assert.AreEqual(-3.0 / 7.0, inverted.Y);
Assert.AreEqual(-6.0 / 7.0, inverted.Z);
}