public void StaticTaxiDistanceWorks(int x1, int y1, int x2, int y2, int distance) { var p = new XYPoint(x1, y1); var q = new XYPoint(x2, y2); Assert.That(XYPoint.DistanceBetween(p, q), Is.EqualTo(distance)); Assert.That(XYPoint.DistanceBetween(q, p), Is.EqualTo(distance)); }