public List<Answer> find(Predicate<Answer> pred) {
return answers.values().stream().filter(pred).collect(Collectors.toList());
}
public List<Answer> classicFind(Predicate<Answer> pred) {
List<Answer> results = new ArrayList<Answer>();
for (Answer answer : answers.values()) if (pred.test(answer)) results.add(answer);
return results;
}