void updateNodeToBucketMap(
      HashMap<InternalDistributedMember, HashMap<Integer, HashSet>> nodeToBuckets,
      HashMap<Integer, HashSet> bucketKeys) {
    for (int id : bucketKeys.keySet()) {
      InternalDistributedMember node = getOrCreateNodeForBucketWrite(id, null);
      if (nodeToBuckets.containsKey(node)) {
        nodeToBuckets.get(node).put(id, bucketKeys.get(id));
      } else {
        HashMap<Integer, HashSet> map = new HashMap<>();
        map.put(id, bucketKeys.get(id));
        nodeToBuckets.put(node, map);
      }
    }
  }
Fetches entries from local and remote nodes and appends these to register-interest response.
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegion.java