svoid test_CutListToBudget() {
  var cutter = new CutListToBudget<S>(s -> (double) l(s));
  cutter.allowPartial((s, l) -> takeFirst(s, iround(l)));
  cutter.maxPrice(3);
  cutter.inputList(ll("aaaaa"));
  assertEqualsVerbose(ll("aaa"), cutter!);
  assertEqualsVerbose("aaaaa", cutter.fullLastElement());
  assertEqualsVerbose(Percent.fromRatio(3.0/5.0), cutter.lastElementKeptPercentage());
}