protected Object reduce(Map<Integer, Object> map) { Collection<Data> list = new LinkedList(); for (Object obj : map.values()) { if (obj == null) { continue; } MultiMapResponse response = (MultiMapResponse) obj; Collection<MultiMapRecord> coll = response.getCollection(); if (coll == null) { continue; } for (MultiMapRecord record : coll) { list.add(serializationService.toData(record.getObject())); } } return new PortableCollection(list); }