public class SimpleServiceWithoutOCP
{
	public void DoSomeWork()
	{
		var stuff = CallTheRepositoryForSomeStuff();

		foreach(var thing in stuff)
			DoSomething(thing);
	}

	private IList<Stuff> CallTheRepositoryForSomeStuff()
	{
		return Repository.GetStuff();
	}

	private void DoSomething(Stuff stuff)
	{
		//doesn't matter what's here
	}
}