code: private static DiscoverInfo restoreInfoFromFile(File file) throws Exception {
          String fileContent;
          try (DataInputStream dis = new DataInputStream(new FileInputStream(file))) {
              fileContent = dis.readUTF();
          }
          if (fileContent == null) {
              return null;
          }
          return PacketParserUtils.parseStanza(fileContent);
      }
docs: Tries to restore an DiscoverInfo stanza from a file.
  
  @param file
  @return the restored DiscoverInfo
  @throws Exception