public function isMarked(string $id): bool
    {
        $count = $this->connection
            ->createQueryBuilder()
            ->select('count(marker)')
            ->from($this->table, 'marker')
            ->where('marker.id = :id')
            ->setParameter('id', $id)
            ->execute()
            ->fetchColumn();

        return $count > 0;
    }
public function isMarked(string $id): bool
    {
        $count = $this->connection
            ->createQueryBuilder()
            ->select('count(marker)')
            ->from($this->table, 'marker')
            ->where('marker.id = :id')
            ->setParameter('id', $id)
            ->execute()
            ->fetchColumn();

        return $count > 0;
    }
{@inheritdoc}