static IterableIterator<L<Int>> allSpreads(final int toSpread, final int buckets) {
  ret iff(new F0 {
    L<Int> collecting = ll(0);
    L<Int> remaining = ll(toSpread);

    public O get() {
      while true {
        ping();
        if (empty(collecting)) ret endMarker();
        
        if (l(collecting) > buckets) {
          dropLast(remaining);
          dropLast(collecting);
          ret cloneList(collecting);
        }
      
        if (last(collecting) < last(remaining)) {
          setLast(collecting, last(collecting)+1);
          remaining.add(last(remaining)-last(collecting));
          collecting.add(0);
        } else {
          dropLast(collecting);
          dropLast(remaining);
        }
      }
    }
  });
}