@Override
    public Optional<Ticket> create(IsSeatTakenDto isSeatTakenDto,
                                   Ticket ticket, HttpSession session) {
        if (isSeatTaken(isSeatTakenDto)) {
            return Optional.empty();
        }
        try (var connection = sql2o.open()) {
            var sql = "INSERT INTO " +
                    "tickets(session_id, row_number, place_number, user_id)" +
                    " VALUES (:sessionId, :rowNumber, :placeNumber, :userId)";
            var query = connection.createQuery(sql, true)
                    .addParameter("sessionId", ticket.getSessionId())
                    .addParameter("rowNumber", ticket.getRowNumber())
                    .addParameter("placeNumber", ticket.getPlaceNumber())
                    .addParameter("userId", session.getAttribute("id"));
            int generatedId = query.executeUpdate().getKey(Integer.class);
            ticket.setId(generatedId);
        } 
        return Optional.of(ticket);
    }

    @Override
    public List<UserDTO> getPostsByUserId(List<Integer> userIds) {
        Map<Integer, UserDTO> userMap = new HashMap<>();

        postRepository.findByUserIdIn(userIds).forEach(post -> {
            int userId = post.getUser().getId();
            userMap.computeIfAbsent(userId, id ->
                    new UserDTO(userId, post.getUser().getFullName(), new ArrayList<>()
            )).getPosts().add(post);
        });

        return new ArrayList<>(userMap.values());
    }

    fun notifyByTaskUpdate(task: Task) {
        scope.launch {
            val template = """
                    Обновлено описание урока ${task.name} [#${task.number}] 
                    https://job4j.ru/profile/exercise/${task.topicId}/task-view/${task.id}"    
                """.trimIndent()
            userRepository
                .findAllByActiveAndPayments()
                .filter { messengerRepository.isUserNotificationOn(it.id) }
                .forEach {
                    bot?.send(it.id, template)
                }
        }
    }

import org.jvnet.hk2.annotations.Service;
import org.springframework.beans.factory.BeanNameAware;
import ru.job4j.content.Content;

@Service
public class BotCommandHandler implements BeanNameAware {
    private String beanName;

class TreeNode {
    private int value;
    private TreeNode left;
    private TreeNode right;

    public TreeNode(int value) {
        this.value = value;
    }

    public int getValue() {
        return value;
    }

    public TreeNode setValue(int value) {
        this.value = value;
        return this;
    }

    public TreeNode getLeft() {
        return left;
    }

    public TreeNode setLeft(TreeNode left) {
        this.left = left;
        return this;
    }

    public TreeNode getRight() {
        return right;
    }

    public TreeNode setRight(TreeNode right) {
        this.right = right;
        return this;
    }

    @Override
    public boolean equals(Object o) {
        // TODO - implement this
        return false;
    }
}

@Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;
    TreeNode treeNode = (TreeNode) o;
    return value == treeNode.value &&
           (left == null ? treeNode.left == null : left.equals(treeNode.left)) &&
           (right == null ? treeNode.right == null : right.equals(treeNode.right));
}