@Override
  public String toString() {
    Map<String, Object> map = new HashMap<>();
    map.put(NUM_SERVERS_QUERIED, getNumServersQueried());
    map.put(NUM_SERVERS_RESPONDED, getNumServersResponded());
    map.put(NUM_DOCS_SCANNED, getNumDocsScanned());
    map.put(NUM_ENTRIES_SCANNED_IN_FILTER, getNumEntriesScannedInFilter());
    map.put(NUM_ENTRIES_SCANNED_POST_FILTER, getNumEntriesScannedPostFilter());
    map.put(NUM_SEGMENTS_QUERIED, getNumSegmentsQueried());
    map.put(NUM_SEGMENTS_PROCESSED, getNumSegmentsProcessed());
    map.put(NUM_SEGMENTS_MATCHED, getNumSegmentsMatched());
    map.put(NUM_CONSUMING_SEGMENTS_QUERIED, getNumConsumingSegmentsQueried());
    map.put(MIN_CONSUMING_FRESHNESS_TIME_MS, getMinConsumingFreshnessTimeMs() + "ms");
    map.put(TOTAL_DOCS, getTotalDocs());
    map.put(NUM_GROUPS_LIMIT_REACHED, isNumGroupsLimitReached());
    map.put(BROKER_REDUCE_TIME_MS, getBrokerReduceTimeMs() + "ms");
    map.put(TIME_USED_MS, getTimeUsedMs() + "ms");
    map.put(PARTIAL_RESULT, isPartialResult());
    return map.toString();
  }
@Test
  public void testToString() {
    // Run the test
    final String result = _executionStatsUnderTest.toString();

    // Verify the results
    assertNotEquals("", result);
  }