@Override
  public Long getLong(String key) {
    final OpType type = OpType.fromSymbol(key);
    return type == null ? null : opsCount.get(type).longValue();
  }
@Test
  public void testGetLong() {
    assertNull(statistics.getLong(null));
    assertNull(statistics.getLong(NO_SUCH_OP));
    verifyStatistics();
  }