code: private static LongConsumer adapt(Sink<Long> sink) {
          if (sink instanceof LongConsumer) {
              return (LongConsumer) sink;
          } else {
  //            if (Tripwire.ENABLED)
  //                Tripwire.trip(AbstractPipeline.class,
  //                              "using LongStream.adapt(Sink<Long> s)");
              return sink::accept;
          }
      }
docs: Adapt a {@code Sink<Long> to an {@code LongConsumer}, ideally simply
  by casting.