@Test
  public void testMinLongNullKeyGroupBySingleBatch() throws HiveException {
    testAggregateLongKeyAggregate(
        "min",
        4,
        Arrays.asList(new Long[]{null,2L,null,02L}),
        Arrays.asList(new Long[]{13L,5L,7L,19L}),
        buildHashMap(null, 7L, 2L, 5L));
  }
Unit test for the vectorized GROUP BY operator.
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/TestVectorGroupByOperator.java