code: @Override
      public SecurityUser save(final UserRequest userRequest) {
          logger.info("save user" + userRequest.getUsername());
          final UserImpl user = new UserImpl();
          user.setUsername(userRequest.getUsername());
          user.setPassword(passwordEncoder.encode(userRequest.getPassword()));
          user.setFirstname(userRequest.getFirstname());
          user.setLastname(userRequest.getLastname());
          user.addRole("USER");
          users.add(user);
          final UsersWriter usersWriter = new UsersWriter(users,
                  users.getUserFileName());
          usersWriter.write();
          return user;
      }
docs: {@inheritDoc}