static RectAndMD5 firstRectAndMD5Containing(L<RectAndMD5> l, int x, int y) {
  for (RectAndMD5 r : unnull(l))
    if (r.r.contains(x, y))
      ret r;
  null;
}

static RectAndMD5 firstRectAndMD5Containing(L<RectAndMD5> l, Pt p) {
  ret firstRectAndMD5Containing(l, p.x, p.y);
}