@Override
  public Iterator<LongStatistic> getLongStatistics() {
    return new LongIterator();
  }
@Test
  public void testGetLongStatistics() {
    short iterations = 0; // number of the iter.hasNext()
    final Iterator<LongStatistic> iter = statistics.getLongStatistics();

    while (iter.hasNext()) {
      final LongStatistic longStat = iter.next();
      assertNotNull(longStat);
      final OpType opType = OpType.fromSymbol(longStat.getName());
      assertNotNull(opType);
      assertTrue(expectedOpsCountMap.containsKey(opType));
      assertEquals(expectedOpsCountMap.get(opType).longValue(),
          longStat.getValue());
      iterations++;
    }

    // check that all the OpType enum entries are iterated via iter
    assertEquals(OpType.values().length, iterations);
  }