code: public static <T, U> BiStream<T, U> of(Stream<T> stream, U obj) {
          return new BiStream<>(stream, obj);
      }
docs: Factory method {@link BiStream} class
  
  @param stream stream objects
  @param obj object which is compared to objects from stream
  @param <T> type of the objects in stream
  @param <U> type of the compared object
  @return BiStream object