def test_equals_4(self):
     self.assertEqual(minimum_sum([], 3), 0)
 def test_equals(self):
     self.assertEqual(minimum_sum([5, 4, 3, 2, 1], 2), 3)
 def test_equals_3(self):
     self.assertEqual(minimum_sum([5, 4, 3, 2, 1], 7), 15)