code: function query(queryString, args, callback) {
    getClient(function (err, client) {
      if (err) { callback(err); }
  
      if (!client) {
        callback('Could not connect to the database');
      }
      else {
        runQuery(client, queryString, args, callback);
      }
    });
  }
docs: db_query() as in Drupal (though callback-based).