code: public static <T> StreamEx<T> of(Spliterator<? extends T> spliterator) {
          return new StreamEx<>(spliterator, StreamContext.SEQUENTIAL);
      }
docs: Returns a sequential {@link StreamEx} created from given
  {@link Spliterator}.
  
  @param <T> the type of stream elements
  @param spliterator a spliterator to create the stream from.
  @return the new stream
  @since 0.3.4