using System;

#nullable enable

public class Program

{

    public static void Main()

    {

​

        if( ReturnSomething() is string textStuff)

        {

            Console.WriteLine("yep");

        }

        else

        {

            Console.WriteLine("nope");

        }

    }

    public static void TestNull(string thisShouldThrowExceptionIfNull)

    {

        ArgumentNullException.ThrowIfNull(thisShouldThrowExceptionIfNull);

        Console.WriteLine(thisShouldThrowExceptionIfNull);

    }

    public static object ReturnSomething()

    {

        return null;

    }

}