@Override
  public Set entrySet(boolean recursive) {
    checkReadiness();
    if (!restoreSetOperationTransactionBehavior) {
      discoverJTA();
    }
    return Collections.unmodifiableSet(new PREntriesSet());
  }
This method returns set of all the entries of this PartitionedRegion(locally or remotely).
Currently, it throws UnsupportedOperationException

@param recursive boolean flag to indicate whether subregions should be considered or not.
@return set of all the entries of this PartitionedRegion

        OVERRIDES
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegion.java