@Test
  public void testRandomAddSubtractInverse() {
    final int N = 1000000;
    int seed = 1427480960;
    Random rand = new Random(seed);
    long l1, l2;
    for (int i = 1; i <= N; i++) {
      l1 = rand.nextLong();
      l2 = rand.nextLong();
      verifyAddSubtractInverse(l1, l2);
    }
  }
Verify that a * b / b == a
for decimal division for scale 0 with integer inputs.

Not valid if abs(a * b) >= 10**38.
common/src/test/org/apache/hadoop/hive/common/type/TestDecimal128.java