code: public final static <T> Tuple2<Stream<T>, Stream<T>> partition(final Stream<T> stream, final Predicate<? super T> splitter) {
          final Tuple2<Stream<T>, Stream<T>> Tuple2 = duplicate(stream);
          return Tuple.tuple(
                            Tuple2._1().filter(splitter), Tuple2._2().filter(splitter.negate()));
      }
docs: Partition a Stream into two one a per element basis, based on predicate's boolean value
  <pre>
  {@code
  ReactiveSeq.of(1, 2, 3, 4, 5, 6).partition(i -> i % 2 != 0)
  
  //Stream[1,3,5], Stream[2,4,6]
  }
  
  </pre>