using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        using var x = MyFactory.CreateImagination();

        //if(x is IDisposable d) d.Dispose();

        //x.Dispose();

        Console.WriteLine("Done");

    }

}

​

public static class MyFactory{

    public static IImagination CreateImagination(){

        return new MyClass("error");

    }

}

​

public interface IImagination : IDisposable{

    string SayHello();

}

​

public class MyClass : MyBase{

    private bool _disposed;

    private readonly IList<int> _largeNumbers;

    public MyClass(string init) : base(init){

        Console.WriteLine("inside my-class");

        _largeNumbers = [10, 23, 45, 99, 102];

        Console.WriteLine("my-class initialized");

    }

    public override string SayHello(){

        return "foobar";

    }

    protected override void Dispose(bool disposing){

        Console.WriteLine($"inside DISPOSE my-class {_disposed}-{disposing}");

        if(!_disposed)

        {

            if(disposing){

                for(var i = _largeNumbers.Count -1; i > 0; i--){

                    _largeNumbers.RemoveAt(i);

                }

                _largeNumbers.Clear();

            }

        }

        base.Dispose(disposing);

        _disposed = true;

    }

}

​

public abstract class MyBase : IImagination, IDisposable {

    private bool _disposed;

    protected IList<int> _smallNumbers;

    public MyBase(string init){

        Console.WriteLine("inside my-base");

        _smallNumbers = [1, 5, 6, 7, 9];

        if(init=="error") return;

        //if(init=="error") throw new Exception("This is an exception! Eek!");

        Console.WriteLine("my-base initialized");

    }

    public abstract string SayHello();

    public void Dispose(){

        Dispose(true);

        GC.SuppressFinalize(this);

    }

    protected virtual void Dispose(bool disposing){

        Console.WriteLine($"inside DISPOSE my-base {_disposed}-{disposing}");

        if(_disposed) return;

        if(disposing){

            for(var i = _smallNumbers.Count -1; i > 0; i--){

                _smallNumbers.RemoveAt(i);

            }

            _smallNumbers.Clear();

        }

        _disposed = true;

    }

    ~MyBase(){

        Dispose(false);

    }

}