code: public static Stream<Long> box(final long[] longs) {
          return new FixedSizeStream<>(longs.length, new Func1<Integer, Long>() {
              @Override
              public Long call(Integer index) {
                  return longs[index];
              }
          });
      }
docs: Creates a new stream of {@link Long} type that contains all items of a given array.
  
  @param longs an array to get items from.
  @return a new stream of {@link Long} type that contains all items of a given array.