protected function setupMongo($dsn, $options)
    {
        try {
            $this->client = new \MongoClient($dsn, $options);
            $this->dbh    = $this->client->selectDB($this->dbName);
        } catch (\MongoConnectionException $e) {
            throw new ModuleException($this, sprintf('Failed to open Mongo connection: %s', $e->getMessage()));
        }
    }