docs: public HyperLogLog merge(CardinalityEstimatorMergeTypes mergingEntry,
                               SplitBrainMergePolicy<HyperLogLog, CardinalityEstimatorMergeTypes> mergePolicy,
                               SerializationService serializationService) {
          serializationService.getManagedContext().initialize(mergingEntry);
          serializationService.getManagedContext().initialize(mergePolicy);
  
          String name = mergingEntry.getKey();
          if (hll.estimate() != 0) {
              CardinalityEstimatorMergeTypes existingEntry = createMergingEntry(serializationService, name, hll);
              HyperLogLog newValue = mergePolicy.merge(mergingEntry, existingEntry);
              if (newValue != null && !newValue.equals(hll)) {
                  setValue(newValue);
                  return hll;
              }
          } else {
              HyperLogLog newValue = mergePolicy.merge(mergingEntry, null);
              if (newValue != null) {
                  setValue(newValue);
                  return hll;
              }
          }
          return null;
      }