code: static TarArchiveEntry defaultDirEntryWithName( final String dirName ) {
          TarArchiveEntry entry = new TarArchiveEntry(dirName, true);
          entry.setUserId(ROOT_UID);
          entry.setUserName(ROOT_NAME);
          entry.setGroupId(ROOT_UID);
          entry.setGroupName(ROOT_NAME);
          entry.setMode(TarArchiveEntry.DEFAULT_DIR_MODE);
          return entry;
      }
docs: Creates a tar directory entry with defaults parameters.
  @param dirName the directory name
  @return dir entry with reasonable defaults