title: Scala equivalent of C#’s extension methods?
body: <p>In C# you can write:</p>
  
  <pre><code>using System.Numerics;
  namespace ExtensionTest {
  public static class MyExtensions {
      public static BigInteger Square(this BigInteger n) {
          return n * n;
      }
      static void Main(string[] args) {
          BigInteger two = new BigInteger(2);
          System.Console.WriteLine("The square of 2 is " + two.Square());
      }
  }}
  </code></pre>
  
  <p>How would this simple <a href="http://en.wikipedia.org/wiki/Extension_method" rel="noreferrer">extension method</a> look like in Scala?</p>