static Pair<O[][], O[]> fillTableWithData_makeData(L<L> rows, S... colNames) {
  Object[][] data = new Object[rows.size()][];
  int w = 0;
  for (int i = 0; i < rows.size(); i++) {
    L l = rows.get(i);
    Object[] r = new Object[l.size()];
    for (int j = 0; j < l.size(); j++) {
      O o = l.get(j);
      if (o instanceof BufferedImage) o = imageIcon((BufferedImage) o);
      ifclass RGBImage
        if (o instanceof RGBImage) o = imageIcon((RGBImage) o);
      endif
      r[j] = o;
    }
    data[i] = r;
    w = Math.max(w, l.size());
  }
  O[] columnNames = new O[w];
  for (int i = 0; i < w; i++)
    columnNames[i] = i < l(colNames) ? colNames[i] : "?";
  ret pair(data, columnNames);
}