using System;

#nullable enable 

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

​

public class Dupa : IInternalFace

{

    Guid[]? IInternalFace.UserIds { get; set; }

}

​

internal interface IInternalFace

{

    Guid[]? UserIds { get; set; }

}