@Override public IntStream stream() { return mapping.stream().mapToInt(i->i); }
@Override public Stream<? extends FMInstance> stream() { return groupList.stream() .flatMap(i -> map.get(i).stream()); }
@Override public Stream<Entry<List<? extends FMInstance>>> streamByGroup() { return groupList.stream() .map(i -> new AbstractInt2ObjectMap.BasicEntry<>(i, map.get(i))); } }