public void TestUncertaintyAddConstant()
        {
            var u1 = new Uncertainty(7.6, 0.2, 0.3);
            var u2 = u1.Add(7);

            Assert.AreEqual(u2, u1 + 7.0);
            Assert.AreEqual(u2, 7.0 + u1);
            Assert.AreEqual(14.6, u2.Value);
            Assert.AreEqual(0.2, u2.LowerUncertainty);
            Assert.AreEqual(0.3, u2.UpperUncertainty);
            Assert.IsFalse(u2.IsRelative);
        }
        public void TestUncertaintyAdd()
        {
            var u1 = new Uncertainty(6, 0.5, 0.2);
            var u2 = new Uncertainty(2.1, 0.1, 0.3);
            var u3 = u1.Add(u2);

            Assert.AreEqual(u3, u1 + u2);
            Assert.AreEqual(8.1, u3.Value);
            Assert.AreEqual(0.6, u3.LowerUncertainty);
            Assert.AreEqual(0.5, u3.UpperUncertainty);
            Assert.IsFalse(u3.IsRelative);
        }