public void CheckFollowerExistsTest() { // act var parent = new User(); var follower = new User { UserId = Guid.NewGuid() }; var followers = new List<User> { follower }; _userRepositoryMock.Setup(x => x.GetChildren(parent)).Returns(followers); var userManager = new UserManager(_userRepositoryMock.Object); // actual userManager.CheckFollowerExists(parent, follower); // assert // never reached }