public void dd_stm_float(float x, float y, float sum)
        {
            float res = new Math.Subtractor().sub(x, y);

            Assert.AreEqual(sum, res);
        }
        public void dd_stm_int(int x, int y, int sum)
        {
            int res = new Math.Subtractor().sub(x, y);

            Assert.AreEqual(sum, res);
        }