public void LengthNotEqualsTest() { var first = new Dictionary <String, String> { { "a0", "abc00" }, { "b1", "abc12" }, { "c2", "abc13" }, { "d3", "abc14" } }; var second = new Dictionary <String, String> { { "a0", "abc00" }, { "b1", "abc12" }, { "c2", "abc13" } }; var actualResult = first.SafeSequenceEqual(second, new KeyValuePairEqualityComparer <String, String>(StringComparer.Ordinal, StringComparer.OrdinalIgnoreCase)); Assert.IsFalse(actualResult); }