docs: public static Relay edit(
        File file, Source upstream, ByteString metadata, long bufferMaxSize) throws IOException {
      RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw");
      Relay result = new Relay(randomAccessFile, upstream, 0L, metadata, bufferMaxSize);
  
      // Write a dirty header. That way if we crash we won't attempt to recover this.
      randomAccessFile.setLength(0L);
      result.writeHeader(PREFIX_DIRTY, -1L, -1L);
  
      return result;
    }