private BucketOperatorWrapper getBucketOperator(
      Map<PartitionedRegion, InternalPRInfo> detailsMap) {
    Set<PartitionRebalanceDetailsImpl> rebalanceDetails =
        new HashSet<>(detailsMap.size());
    for (Map.Entry<PartitionedRegion, InternalPRInfo> entry : detailsMap.entrySet()) {
      rebalanceDetails.add(new PartitionRebalanceDetailsImpl(entry.getKey()));
    }
    BucketOperator operator =
        simulate ? new SimulatedBucketOperator() : new BucketOperatorImpl(this);
    BucketOperatorWrapper wrapper =
        new BucketOperatorWrapper(operator, rebalanceDetails, stats, leaderRegion);
    return wrapper;
  }
For FPR we will creatd buckets and make primaries as specified by FixedPartitionAttributes. We
have to just create buckets and make primaries for the local node.

@return the details of the rebalance.
geode-core/src/main/java/org/apache/geode/internal/cache/partitioned/PartitionedRegionRebalanceOp.java