For blog2 Sample

Sample.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Sample
{
    class Entity
    {
        public int Id { get; set; }
        public DateTime? Registered { get; set; }
    }

    class User : Entity
    {
        public string Name { get; set; }
        public string EMail { get; set; }
    }

    interface IRepository<TEntity> where TEntity : Entity
    {
        TEntity Get();
    }

    class UserRepository : IRepository<User>
    {
        public User Get() => new User();
    }


}