class ConcurrentHashMultimap implements Multimap<K, V> {

    @Override
    public boolean containsEntry(@Nullable Object key, @Nullable Object value) {
        final Object id = valueIdentityExtractor.apply((V) value);
        return entries.get(key).containsKey(id);
    }

    public  ConcurrentHashMultimap(ValueIdentityExtractor<V> valueIdentityExtractor, ConflictResolver<V> conflictResolver);

}