docs: @Override
      public FileBuilder addDirectory(Path target) throws IOException
      {
          checkTarget(target);
          FileBuilder fb = new FileBuilder();
          fb.target = target;
          fb.content = ByteBuffer.allocate(0);
          fb.size = fb.content.limit();
          fb.mode = 040000;
          fb.compressFilename();
          fileBuilders.add(fb);
          return fb;
      }