### Question:
HalfArithmetic { public int sum(int... nums) { LOGGER.info("Arithmetic sum {}", VERSION); return newSource.accumulateSum(nums); } HalfArithmetic(HalfSource newSource, OldSource oldSource); int sum(int... nums); int mul(int... nums); boolean ifHasZero(int... nums);  }### Answer:
@Test public void testSum() { assertEquals(0, arithmetic.sum(-1, 0, 1)); }