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