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());
        }