code: @Override
      public Collection<Person> findBySurname(final FinderObject owner,
              final String surname) {
          final Root root = (Root) owner;
          final RootVisitor visitor = new RootVisitor();
          root.accept(visitor);
          final List<Person> matches = new ArrayList<>();
          for (final Person person : visitor.getPersons()) {
              final String personSurname = person.getSurname();
              if (personSurname.equals(surname)) {
                  matches.add(person);
              }
          }
  
          Collections.sort(matches, new PersonComparator());
  
          return matches;
      }
docs: {@inheritDoc}