question: public static ReactiveSeq < Integer > range ( final int start , final int end ) { final ReversingRangeIntSpliterator range = new ReversingRangeIntSpliterator ( start , end , false ) ; return StreamUtils . reactiveSeq ( StreamSupport . stream ( range , false ) , Optional . ofNullable ( range ) ) ; }
target:  Create an efficiently reversable Sequence that produces the integers between start and end