public void MutableForEachTest_ShouldEnumerateEntryAsMutable1() { // Arrange var entries = new Hashtable(); entries.Add("a", 1); entries.Add("d", 4); entries.Add("b", 2); entries.Add("c", 3); entries.Add("e", 5); // Act entries.MutableForEach((@this, entry) => { @this[entry.Key] = (int)@this[entry.Key] * (int)@this[entry.Key]; }); // Assert CollectionAssert.AreEqual( new int[] { 1, 4, 9, 16, 25 }.AsEnumerable(), entries.OfType<DictionaryEntry>().Select(_ => (int)_.Value).OrderBy(_ => _) ); }