static <A> L<A> takeFirst_cloneIfDifferent(L<A> l, int n) {
  ret l(l) <= n ? l : subList_cloneIfDifferent(l, 0, n);
}

static <A> L<A> takeFirst_cloneIfDifferent(int n, L<A> l) {
  ret takeFirst_cloneIfDifferent(l, n);
}