long sumCount() {
    CounterCell[] as = counterCells;
    CounterCell a;
    long sum = baseCount;
    if (as != null) {
      for (final CounterCell counterCell : as) {
        if ((a = counterCell) != null) {
          sum += a.value;
        }
      }
    }
    return sum;
  }
Per-thread counter hash codes. Shared across all instances.
geode-core/src/main/java/org/apache/geode/internal/concurrent/CompactConcurrentHashSet2.java