@Override
  public String[] listAll() throws IOException {
    ensureOpen();
    String[] array = fs.listFileNames().toArray(new String[] {});
    Arrays.sort(array);
    return array;
  }
Create a region directory with a given file and chunk region. These regions may be bucket
regions or they may be replicated regions.
geode-lucene/src/main/java/org/apache/geode/cache/lucene/internal/directory/RegionDirectory.java