protected function setupMongoDB($dsn, $options)
    {
        try {
            $this->client = new \MongoDB\Client($dsn, $options);
            $this->dbh    = $this->client->selectDatabase($this->dbName);
        } catch (\MongoDB\Driver\Exception $e) {
            throw new ModuleException($this, sprintf('Failed to open Mongo connection: %s', $e->getMessage()));
        }
    }