@Test
  public void testVarianceLongSimple () throws HiveException {
    testAggregateLongAggregate(
        "variance",
        2,
        Arrays.asList(new Long[]{13L,5L,7L,19L}),
        (double) 30L);
  }
Unit test for the vectorized GROUP BY operator.
ql/src/test/org/apache/hadoop/hive/ql/exec/vector/TestVectorGroupByOperator.java