code: public final static <T> Stream<Vector<T>> grouped(final Stream<T> stream, final int groupSize) {
          return StreamSupport.stream(new GroupingSpliterator<>(stream.spliterator(),()->Vector.empty(),
                  c->Vector.fromIterable(c),groupSize),stream.isParallel());
  
  
      }
docs: Group elements in a Stream by size
  
  <pre>
  {@code
  List<List<Integer>> list = Streams.grouped(Stream.of(1,2,3,4,5,6)
  ,3)
  .collect(CyclopsCollectors.toList());
  
  
  assertThat(list.getValue(0),hasItems(1,2,3));
  assertThat(list.getValue(1),hasItems(4,5,6));
  }
  </pre>
  @param stream Stream to group
  @param groupSize
  Size of each Group
  @return Stream with elements grouped by size