public function subscriptionsWithValueForProperty($property, $value)
 {
     /* Returns array of subscriptions */
     $database = new SQLite3($this->databaseName);
     $query = $database->arrayQuery("SELECT * FROM Subscription WHERE {$property} = '{$value}'");
     $subscriptions = new ArrayObject();
     foreach ($query as $row) {
         $subscriptions->append($row);
     }
     unset($database);
     return $subscriptions;
 }