C#

namespace ConsoleApplication379
{
    class ReferenceTest
    {
        public string Bla { get; set; }
    }
    class Program
    {
        static void Main(string[] args)
        {
            var a = new ReferenceTest() { Bla = "Test" };
            change(a);
            Console.WriteLine(a.Bla);
            Console.ReadLine();
        }
        static void change(ReferenceTest whichOne)
        {
            whichOne.Bla = "Hello World";
        }
    }
}

Bastard Programmer from Hell
If you can't read my code, try converting it here[^]

public static class IntegerExtensions
{
  public static bool Between(this int value, int startRange, int endRange) // Note the special "this" word. That's the thing that says this is an extension method
  {
    return value >= startRange && value <= endRange;
  }
}

int checker = 10;
if (checker.Between(0, 50)
{
  Console.WriteLine("I'm in the range");
}

if (IntegerExtensions.Between(checker, 0, 50))

writer.WriteStartDocument(true)

<?xml version="1.0" encoding="ISO-8859-1" standalone="true"?>

writer.WriteStartDocument(false)

<?xml version="1.0" encoding="ISO-8859-1"?>

<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>