public void OnlyRemovePresentFilters( IFilter[] filtersToAdd, List<IFilter> filters, Mock<IArgumentNullExceptionFixture> fixtureMock) { // Arrange fixtureMock.SetupGet(f => f.Filters).Returns(filters); IFilter[] originalFilters = filters.ToArray(); // Act IArgumentNullExceptionFixture actual = fixtureMock.Object .AddFilters(filtersToAdd) .RemoveFilters(originalFilters) .RemoveFilters(originalFilters); // Asserts Assert.Same(fixtureMock.Object, actual); Assert.Equal(filtersToAdd.Length, filters.Count); Assert.False(filtersToAdd.Except(filters).Any()); }