public void DoRangeTest() { Range <string> stringRange = RangeFactory.CreateRange(null, "cdf"); string actual = stringRange.ToString(); Assert.AreEqual("{ NULL : cdf }", actual); Assert.IsTrue(stringRange.Contains("abc")); Assert.IsFalse(stringRange.Contains("xyz")); stringRange = RangeFactory.CreateRange("xyz", "abc"); actual = stringRange.ToString(); Assert.AreEqual("{ abc : xyz }", actual); Assert.IsTrue(stringRange.Contains("abc")); Assert.IsTrue(stringRange.Contains("cfdes")); Assert.IsTrue(stringRange.Contains("xyz")); Assert.IsFalse(stringRange.Contains("aa")); Assert.IsFalse(stringRange.Contains("zz")); ValueRange <int> intRange = RangeFactory.CreateValueRange <int>(1, null); actual = intRange.ToString(); Assert.AreEqual("{ 1 : NULL }", actual); Assert.IsTrue(intRange.Contains(2)); Assert.IsTrue(intRange.Contains(int.MaxValue)); Assert.IsFalse(intRange.Contains(int.MinValue)); }