@Test
public void testCopyDataFrom() {

	HistoryObserver copy = new HistoryObserver(board);
	board.play("b1");
	observer.update(BLACK, at("e2"), new ShortList(0));
	copy.copyDataFrom(observer);
	assertEquals(at("b1"), copy.get(0));
	assertEquals(at("e2"), copy.get(1));
	copy.update(WHITE, at("c1"), new ShortList(0));
	copy.copyDataFrom(observer);
	copy.update(WHITE, at("a2"), new ShortList(0));
	assertEquals(at("a2"), copy.get(2));
}