J>    public class User
J>    {
J>        public Guid Id { get; private set; }

J>        public string UserName { get; private set; }

J>        public string Info { get; private set; }

J>        public ContactInformation ContactInformation { get; private set; }

J>        protected internal User() { }

J>        /// <summary>
J>        /// Used for loading for ex. from the DB
J>        /// </summary>
J>        public static User Create(Guid id, string userName, string info, ContactInformation contactInformation)
J>        {
J>            return new User
J>            {
J>                Id = id,
J>                Info = info,
J>                UserName = userName,
J>                ContactInformation = contactInformation,
J>            };
J>        }

J>        /// <summary>
J>        /// Used for creation 
J>        /// </summary>
J>        public static User Create(string userName, string info, ContactInformation contactInformation)
J>        {
J>            if (string.IsNullOrWhiteSpace(userName))
J>            {
J>                throw new ArgumentException();
J>            }
J>            // other validation ...

J>            var id = Guid.NewGuid();

J>            return Create(id, info, userName, contactInformation);
J>        }

J>        public virtual ContactInformation GetContactInformation() => ContactInformation;

J>        public virtual void UpdateInformation(string info, string email)
J>        {
J>            // validation ..

J>            this.Info = info;
J>            GetContactInformation().UpdateEmail(email);
J>        }
J>    }
J>    public class ContactInformation
J>    {
J>        public Guid Id { get; private set; }

J>        public string Phone { get; private set; }

J>        public string Email { get; private set; }

J>        protected internal ContactInformation() { }

J>        public static ContactInformation Create(Guid id, string phone, string email) => new ContactInformation
J>        {
J>            Id = id,
J>            Phone = phone,
J>            Email = email
J>        };

J>        public static ContactInformation Create(string phone, string email)
J>        {
J>            var id = Guid.NewGuid();
J>            return Create(phone, email);
J>        }

J>        public static ContactInformation Create(string email) => Create(null, email);

J>        internal virtual void UpdateEmail(string newEmail)
J>        {
J>            if (newEmail.Contains("admin"))
J>            {
J>                throw new ArgumentException();
J>            }

J>            this.Email = newEmail;
J>        }
J>    }

J>

J>    public class UserRepository
J>    {

J>        public User Load(Guid id)
J>        {
J>            // Loading from the DB ...
J>            var contactInformation = ContactInformation.Create(Guid.NewGuid(), "bob@example.com", "+123456");
J>            var user = User.Create(id, "Bob", "Smth", contactInformation);
J>            return user;
J>        }
J>        public void Save(User user)
J>        {

J>        }
J>    }
J>

J>   public class UserInformationDto
J>    {
J>        public string Email { get; set; }
J>        public string Info { get; set; }
J>    }

J>    public class UserService
J>    {

J>        // IUserRepository
J>        private UserRepository userRepository;

J>        public UserService(UserRepository userRepository)
J>        {
J>            this.userRepository = userRepository;
J>        }

J>        public void UpdateUserInformation(Guid userId, UserInformationDto userInformation)
J>        {

J>            // validation ..

J>            var user = userRepository.Load(userId);

J>            user.UpdateInformation(userInformation.Info, userInformation.Email);

J>            userRepository.Save(user);
J>        }
J>    }
J>