static <A> L<A> subList(L<A> l, int startIndex) {
  ret subList(l, startIndex, l(l));
}

static <A> L<A> subList(int startIndex, L<A> l) {
  ret subList(l, startIndex);
}

static <A> L<A> subList(int startIndex, int endIndex, L<A> l) {
  ret subList(l, startIndex, endIndex);
}

static <A> L<A> subList(L<A> l, int startIndex, int endIndex) {
  if (l == null) null;
  int n = l(l);
  startIndex = Math.max(0, startIndex);
  endIndex = Math.min(n, endIndex);
  if (startIndex > endIndex) ret ll();
  if (startIndex == 0 && endIndex == n) ret l;
  ifdef OurSubLists
    ret ourSubList_noRangeCheck(l, startIndex, endIndex);
  endifdef
  ifndef OurSubLists
    ret l.subList(startIndex, endIndex);
  endifndef
}

ifclass IntRange
static <A> L<A> subList(L<A> l, IntRange r) {
  ret subList(l, r.start, r.end);
}
endif

Began life as a copy of #1001911