private void ReturnsEnumerationOfMethodData( [Frozen] Mock<IArgumentNullExceptionFixture> fixtureMock, ICollection<MethodData> expectedData, MethodInfo unused1, CustomAttribute sut) { // Arrange fixtureMock.Setup(f => f.GetData()).Returns(expectedData); // Act List<MethodData> actualData = sut.GetData(unused1) .SelectMany(d => d.OfType<MethodData>()) .ToList(); // Assert Assert.Equal(expectedData.Count, actualData.Count); Assert.False(expectedData.Except(actualData).Any()); }