*<Null safety>*
void shuffleRange (int start, int end, [Random? random])
void shuffleRange(int start, int end, [Random? random]) { if (source.length != _initialSize) { throw ConcurrentModificationError(source); } RangeError.checkValidRange(start, end, length); algorithms.shuffle(source, this.start + start, this.start + end, random); }