@Override
  public UserDto convertTo(User source, UserDto dest) {
    if (dest == null) {
      dest = new UserDto();
    }

    dest.setId(source.getId().toString());
    dest.setLogin(source.getUsername());
    dest.setRoles(toString(source.getRoles()));

    return dest;
  }
  @Override
  public User convertFrom(UserDto source, User dest) {
    if (dest == null) {
      dest = new User();
    }

    dest.setId(new Long(source.getId()));
    dest.setLogin(source.getLogin());
    dest.getAuthorities().clear();
    dest.getAuthorities().addAll(toAuthorities(dest, source.getRoles()));

    return dest;
  }