### Question:
LongCollectorImpl implements LongCollector<A, R> { @Override public ObjLongConsumer<A> accumulator() { return accumulator; } LongCollectorImpl(
            final Supplier<A> supplier,
            final ObjLongConsumer<A> accumulator,
            final BinaryOperator<A> combiner,
            final Function<A, R> finisher,
            final Set<Collector.Characteristics> characteristics); @Override Supplier<A> supplier(); @Override ObjLongConsumer<A> accumulator(); @Override BinaryOperator<A> combiner(); @Override Function<A, R> finisher(); @Override Set<Collector.Characteristics> characteristics();  }### Answer:
@Test void accumulator() { assertSame(ACCUMULATOR, COLLECTOR.accumulator()); }