@Test
  public void testUpdateWithScale() {
    Decimal128 d1 = new Decimal128(1234.123, (short)4);
    Decimal128 d2 = new Decimal128(0, (short)3);
    d2.update(d1, (short)3);
    assertEquals(0, d1.compareTo(d2));
  }
During earlier code testing, if we found errors, test them here as regression tests.
common/src/test/org/apache/hadoop/hive/common/type/TestDecimal128.java