def test_empty(self):
self.assertEqual(balance_point([]), None)
def test_finds_first(self):
self.assertEqual(balance_point([2, 4, 0, 0, 0, 2, 4]), 2)
def test_simple(self):
self.assertEqual(balance_point([1, 2, 1]), 1)
def test_0_one_side(self):
self.assertEqual(balance_point([1, 0]), 0)
self.assertEqual(balance_point([0, 1]), 1)
def test_example(self):
self.assertEqual(balance_point([1, 2, 9, 4, -1]), 2)