AssertionLibrary.cs

namespace Hypothetical.Assertion.Library
{
    public static class Assert
    {
        public static void AreEqual(int expected, int actual)
        {
            if (expected != actual)
                throw new AssertionException(String.Format("Expected {0} but was {1}.", expected, actual));
        }
    }

    public class AssertionException : Exception
    {
        public AssertionException(string message)
            : base(message)
        {
        }
    }
}