async getSubscribers(userId, taskId) {
    const query = `
         WITH t_task AS
  (SELECT *
   FROM ${env.table_tasks}
   WHERE id = $2),
     t_subscriptions AS
  (SELECT s.id,
          s.user_id
   FROM t_task,
        ${env.table_subscriptions} s
   WHERE ((ST_DistanceSphere (t_task.the_geom, t_task.the_geom) <= t_task.radius)
          AND (ST_DistanceSphere (t_task.the_geom, s.the_geom) <= s.radius))
     AND s.user_id != $1
     AND s.is_active = TRUE),
     t_tags AS
  (SELECT *
   FROM ${env.table_subscriptions_tags}
   WHERE subscription_id IN
       (SELECT id
        FROM t_subscriptions)),
     t_ids_no_tags AS
  (SELECT id
   FROM
     (SELECT t_subscriptions.id,
             count(t_tags.subscription_id) AS total
      FROM t_subscriptions
      LEFT JOIN t_tags ON t_subscriptions.id = t_tags.subscription_id
      GROUP BY t_subscriptions.id) t_res
   WHERE t_res.total = 0 ),
     t_ids_tags AS
  (SELECT subscription_id
   FROM
     (SELECT subscription_id,
             (to_tsvector(t_task.body) @@ plainto_tsquery(tag)) is_found
      FROM t_tags,
           t_task
      GROUP BY subscription_id,
               is_found) t
   WHERE t.is_found = TRUE ),
     t_ids AS
  (SELECT *
   FROM t_ids_no_tags
   UNION ALL SELECT *
   FROM t_ids_tags)
SELECT user_id ,
       array_agg(id) as subscriptions
FROM
  (SELECT *
   FROM t_subscriptions
   WHERE id IN
       (SELECT *
        FROM t_ids)
   GROUP BY user_id,
            id) t_res
GROUP BY user_id
        `;
    return await this.request(query, [userId, taskId]);
  }