public static void TestVector3Constructor()
    {
        Vector3d v0 = new Vector3d();
        v0.x.ShouldBe(0); v0.y.ShouldBe(0); v0.z.ShouldBe(0);

        Vector3d v1 = new Vector3d(5);
        v1.x.ShouldBe(5); v1.y.ShouldBe(0); v1.z.ShouldBe(0);

        Vector3d v2 = new Vector3d(5, 6);
        v2.x.ShouldBe(5); v2.y.ShouldBe(6); v2.z.ShouldBe(0);

        Vector3d v3 = new Vector3d(5, 6, 7);
        v3.x.ShouldBe(5); v3.y.ShouldBe(6); v3.z.ShouldBe(7);

        Vector3d v4 = new Vector3d(5, 6, 7, 8);
        v4.x.ShouldBe(5); v4.y.ShouldBe(6); v4.z.ShouldBe(7);

        Vector3d v5 = new Vector3d(v3);
        v5.ShouldBe(v3);
    }