public void SortOnKeysTest() { IDictionary<double, double> dictionary = new Dictionary<double, double> { { -5F, 1F }, { -2F, 0.2F }, { -7F, 0.4F }, { 10F, 1F } }; var expected = new SortedDictionary<double, double> { { -5F, 1F }, { -2F, 0.2F }, { -7F, 0.4F }, { 10F, 1F } }; SortedDictionary<double, double> actual = dictionary.SortOnKeys(); foreach (double key in actual.Keys) { Assert.That(actual[key], Is.EqualTo(expected[key]).Within(1).Percent); } }