public void FromXna()
{
Vector4 xna = new Vector4(6, 7, 8, 9);
Vector4D v = Vector4D.FromXna(xna);
Assert.AreEqual(xna.X, v.X);
Assert.AreEqual(xna.Y, v.Y);
Assert.AreEqual(xna.Z, v.Z);
Assert.AreEqual(xna.W, v.W);
}