using System;

public class Program

{

    public static void Main()

    {

        var src = "abcd";

        // Obviously, PadLeft works fine normally

        Console.WriteLine(src.PadLeft(10, '-'));

        // PadLeft "works right" when padding less then length: it returns with no changes

        Console.WriteLine(src.PadLeft(2, '-'));

        // But it does fail with nulls

        string src2 = null;

        Console.WriteLine(src2.PadLeft(2, '-'));

    }

}