public void processAnswer(Long id, String message){
        if (!recommendations.containsKey(id))
            return;
        Recommendation rec = recommendations.get(id);
        rec.setMessage(message);
        if (queries.containsKey(rec.getWriter().getId())){
            queries.get(rec.getWriter().getId()).remove(rec);
        }
        if (rec.getSelf()){
            if (!self.containsKey(rec.getSender().getId()))
                self.put(rec.getSender().getId(),new LinkedHashSet<Recommendation>());
            self.get(rec.getSender().getId()).add(rec);
        } else {
            if (!inbox.containsKey(rec.getSender().getId()))
                inbox.put(rec.getSender().getId(),new LinkedHashSet<Recommendation>());
            inbox.get(rec.getSender().getId()).add(rec);
        }
    }