*<Null safety>*
bool isSortedBy <K extends Comparable<K>>(K keyOf(T element))
bool isSortedBy<K extends Comparable<K>>(K Function(T element) keyOf) { var iterator = this.iterator; if (!iterator.moveNext()) return true; var previousKey = keyOf(iterator.current); while (iterator.moveNext()) { var key = keyOf(iterator.current); if (previousKey.compareTo(key) > 0) return false; previousKey = key; } return true; }