@Test
  public void testSumLongZero () throws HiveException {
    testAggregateLongAggregate(
        "sum",
        2,
        Arrays.asList(new Long[]{-(long)Integer.MAX_VALUE, (long)Integer.MAX_VALUE}),
        0L);
  }
Unit test for the vectorized GROUP BY operator.
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/TestVectorGroupByOperator.java