static <MySSI extends AbstractSSI> L<MySSI> takeFirstNSSILines(int maxLines, Iterable<MySSI> l) {
  int sum = 0;
  new L<SSI> out;
  fOr (ssi : l) {
    if (sum >= maxLines) break;
    
    int linesToCopy = min(ssi.height(), maxLines-sum);
    out.add(linesToCopy == ssi.height() ? ssi : ssi.topPart(linesToCopy));
    sum += ssi.height();
  }
  ret out;
}