public void EmptyIfNull_WithNullEnumerable_ShouldNewEnumerable() { // Arrange System.Collections.IEnumerable enumerable = null; System.Collections.ICollection collection = null; System.Collections.IList list = null; // Act System.Collections.IEnumerable result1 = enumerable.EmptyIfNull(); System.Collections.ICollection result2 = collection.EmptyIfNull(); System.Collections.IList result3 = list.EmptyIfNull(); // Assert Assert.True(result1.IsEmpty()); Assert.True(result2.IsEmpty()); Assert.True(result3.IsEmpty()); }