code: public int readMessages(Reader is, OutboxAmp outbox)
      throws IOException
    {
      Objects.requireNonNull(outbox);
      
      JsonReaderImpl jIn = new JsonReaderImpl(is, _jsonFactory);
        
      return readMessages(jIn, outbox);
    }
docs: Reads the next HMTP packet from the stream, returning false on
  end of file.