public void joinToChatRoom(Token token, UserId userId, ChatRoomId chatRoomId)
      throws AuthenticationException, UserNotFoundException, ChatRoomNotFoundException {

    LOG.info(format("Join user with id[%d] into chat-room with id[%d].", userId.id, chatRoomId.id));

    ChatRoom chatRoom = getChatRoom(chatRoomId);
    User user = getUser(userId);

    user.getChatRooms().add(chatRoom);
    userRepository.save(user);

    LOG.info(
        format(
            "Joined user with id[%d] into chat-room with id[%d] was successfully.",
            userId.id, chatRoomId.id));
  }