public void Line_rotateZ_returnsVal()
{
ILine3 line = new Line3(1, 1, 0, 2, 2, 0);
Vector3 pc = new Vector3(0, 0, 0);
ILine3 lrot = line.RotateZ(pc, Math.PI);
Assert.AreEqual(line.Length, lrot.Length, "len");
Assert.AreEqual(-1d, Math.Round(lrot.Point1.X, 8), "x1");
Assert.AreEqual(-1d, Math.Round(lrot.Point1.Y, 8), "y1");
Assert.AreEqual(0d, Math.Round(lrot.Point1.Z, 8), "z1");
}