class BiCardSource implements CardSource {

	@Override
	public Card draw()
	{
		if( !aSource1.isEmpty() )
		{
			return aSource2.draw();
		}
		else
		{
			return aSource1.draw();
		}
	}

}

class TestBiCardSource {

	private static final Card ACE;
	private static final Card TWO;
	private CardSource aEmpty;
	private CardSource aContainsAce;
	private CardSource aContainsTwo;

	@Test
	public void testDraw_SecondEmpty()
	{

		assertSame(ACE, new BiCardSource(aContainsAce, aEmpty).draw());
	}

}