public function __construct(\MongoClient $connection, $ns)
{
$this->connection = $connection;
$this->ns = $ns;
$nsParts = explode('.', $ns);
$dbName = array_shift($nsParts);
$collectionName = implode('.', $nsParts);
$this->db = $connection->selectDB($dbName)->getDb();
if ($collectionName) {
$this->collection = $connection->selectCollection($dbName, $collectionName)->getCollection();
}
}