Group.RemoveUser C# (CSharp) Method

    public void RemoveUser(string userID)
    {
    }

        public void RemoveUser_RemoveUserFromGroup()
        {
            var users = SetupGroupWithUsers();

            var result = _group.RemoveUser(users.First());

            Assert.IsNotNull(result);
            Assert.AreEqual(0, result.Users.Count());
        }