code: public static Optional<Token<?>> getTokenFromSeqFile(String userNameKey, Path tokenFilePath) throws IOException {
      log.info("Reading tokens from sequence file " + tokenFilePath);
  
      try (Closer closer = Closer.create()) {
        FileSystem localFs = FileSystem.getLocal(new Configuration());
        @SuppressWarnings("deprecation")
        SequenceFile.Reader tokenReader =
            closer.register(new SequenceFile.Reader(localFs, tokenFilePath, localFs.getConf()));
        Text key = new Text();
        Token<?> value = new Token<>();
        while (tokenReader.next(key, value)) {
          log.debug("Found token for user: " + key);
          if (key.toString().equals(userNameKey)) {
            return Optional.<Token<?>> of(value);
          }
        }
      }
      log.warn("Did not find any tokens for user " + userNameKey);
      return Optional.absent();
    }
docs: Retrives a {@link Token} from a given sequence file for a specified user. The sequence file should contain a list
  of key, value pairs where each key corresponds to a user and each value corresponds to a {@link Token} for that
  user.
  
  @param userNameKey The name of the user to retrieve a {@link Token} for
  @param tokenFilePath The path to the sequence file containing the {@link Token}s
  
  @return A {@link Token} for the given user name