public void EnvelopeTest()
        {
            var env = GeometryFactory <int> .CreatEnvelope();

            var rect1 = GeometryFactory <int> .CreateRectangle(1, -20, 40, -10);

            var rect2 = GeometryFactory <int> .CreateRectangle(-20, -10, 10, 0);

            env.Expand(rect1);
            env.Expand(rect2);

            Assert.AreEqual(env.Start.X, -20);
            Assert.AreEqual(env.Start.Y, -20);

            Assert.AreEqual(env.End.X, 40);
            Assert.AreEqual(env.End.Y, 0);
        }
        public static void EnvelopeTest()
        {
            Console.WriteLine("Start of envelope test.");

            var env = GeometryFactory <int> .CreatEnvelope();

            var rect1 = GeometryFactory <int> .CreateRectangle(1, -20, 40, -10);

            var rect2 = GeometryFactory <int> .CreateRectangle(-20, -10, 10, 0);

            env.Expand(rect1);
            env.Expand(rect2);

            Console.WriteLine("min = {0}, {1}", env.Min.X, env.Min.Y);
            Console.WriteLine("max = {0}, {1}", env.Max.X, env.Max.Y);

            Console.WriteLine("End of envelope test.");
        }