code: public static Function<? super ReactiveSeq<Integer>, ? extends ReactiveSeq<Integer>> concatInts( ReactiveSeq<Integer> b){
          return a->ReactiveSeq.fromSpliterator(IntStream.concat(a.mapToInt(i->i),b.mapToInt(i->i)).spliterator());
      }
docs: /*
  Fluent integer concat operation using primitive types
  e.g.
  <pre>
  {@code
  import static cyclops.ReactiveSeq.concatInts;
  
  ReactiveSeq.ofInts(1,2,3)
  .to(concatInts(ReactiveSeq.range(5,10)));
  
  //[1,2,3,5,6,7,8,9]
  }
  </pre>