public void generateBackedUpDiskStores(
      Map<DistributedMember, Set<PersistentID>> backedUpDiskStores) {
    Map<String, String[]> diskStores = new HashMap<>();
    backedUpDiskStores.entrySet().forEach(entry -> {
      DistributedMember member = entry.getKey();
      Set<PersistentID> ids = entry.getValue();
      String[] setOfDiskStr = new String[ids.size()];
      entry.getValue().stream().map(PersistentID::getDirectory).collect(Collectors.toList())
          .toArray(setOfDiskStr);
      diskStores.put(member.getId(), setOfDiskStr);
    });
    setBackedUpDiskStores(diskStores);
  }
Sets the map of member names/IDs and the {@link PersistentID} of the disk stores that were
backed up.
geode-core/src/main/java/org/apache/geode/management/internal/DiskBackupStatusImpl.java