compareKeys method

@override int compareKeys(int idx1, int idx2)

Implementation

@override
int compareKeys(int idx1, int idx2) {
  if (keys == null) {
    throw StateError('Cannot sort keys when the keys list is null');
  }
  final c = comparer.sort(keys![idx1], keys![idx2]);
  if (c == 0) {
    if (next == null) return idx1 - idx2;
    return next!.compareKeys(idx1, idx2);
  }
  return descending ? -c : c;
}