using System;

public class Entity: INamed

{

    public string Name { get; set; }

}

​

public class Entity2: INamed

{

    public string Name { get; set; }

}

​

public interface INamed

{

    public string Name { get; set; }

}

​

public static class EntityExtensions

{

    public static void SetName(this INamed source, string name)

    {

        if(string.IsNullOrEmpty(name))

        {

            return;

        }

        source.Name = name;

    }

}

​

public class Program

{

    public static void Main()

    {

        var a = new Entity();

        a.SetName("test");

        Console.WriteLine("Hello World");

    }

}