@Override public BiConsumer<BiMap<K, U>, T> accumulator() { return (map, data) -> { K key = keyMapper.apply(data); U value = valueMapper.apply(data); map.merge(key, value, mergeFunction); }; }
@Override public BinaryOperator<BiMap<K, U>> combiner() { return (map, another) -> { another.forEach((key, value) -> map.merge(key, value, mergeFunction) ); return map; }; } }