code: public static ShortStream zip(final ShortStream a, final ShortStream b, final ShortStream c, final ShortTriFunction<Short> zipFunction) {
          return Stream.zip(a, b, c, zipFunction).mapToShort(ToShortFunction.UNBOX);
      }
docs: Zip together the "a", "b" and "c" streams until one of them runs out of values.
  Each triple of values is combined into a single value using the supplied zipFunction function.
  
  @param a
  @param b
  @return