def test_get_none_position_3(self):
board = PuzzleBoard(size=2, state=[[1, None], [2, 3]])
none_position = board.get_none_position()
self.assertEqual(none_position, (1, 0))
def test_get_none_position_2(self):
board = PuzzleBoard(size=2, state=[[1, 1], [None, 3]])
none_position = board.get_none_position()
self.assertEqual(none_position, (0, 1))