using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var a = new List<Test>();

        a = null;

        var b = a.ToDictionary(x => x.TestInt);

        Console.WriteLine("Hello World");

    }

}

​

public class Test

{

    public int TestInt {get; set;}

}