docs: function updateTask(task, callback) {
      database.serialize(function() {
        var expiry_time = getExpiryTime(task);
        var update_task = "UPDATE "+table_name+" SET task = ?, "
        +"at = datetime("+expiry_time+") WHERE "+table_name+".id = ?";
  
        log.debug('sqlite-adapter','Running query:',update_task);
        database.run(update_task, JSON.stringify(task), task.id, function(error) {
          if (error) {
            callback(error);
          }
          callback(error, this.changes);
        });
      });
    }