public void GetSkillRatings_Flow_IEnumerableDouble() { var rating = 7.0; var user = new User { UserSkills = new List <UserSkill> { new UserSkill { Ratings = new List <Rating> { new Rating { Mark = rating } }, } } }; var result = UserExtension.GetSkillRatings(user); Assert.AreEqual(rating, result.Average()); }