def test_position_adjacent(self):
		origin = Position(0, 0)
		cardinals = [Position(0,1),
		             Position(1,0),
		             Position(-1, 0),
		             Position(0, -1)]
		self.maxDiff = None
		self.assertItemsEqual([p for p in origin.adjacent()], cardinals)
	def test_position_shift(self):
		origin = Position(0, 0)
		diagonal_down_right = origin.shift(1, 1)
		self.assertTrue(origin is not diagonal_down_right)
		self.assertEqual(diagonal_down_right.x(), 1)
		self.assertEqual(diagonal_down_right.y(), 1)