public function setUp()
{
// connect to mongo
$client = new Client(getenv('PHPMONGO_DSN') ? getenv('PHPMONGO_DSN') : null);
if (version_compare($client->getDbVersion(), '2.6.0', '<')) {
$this->markTestSkipped('Current primary does not have a Write API support.');
}
// select database
$database = $client->getDatabase('test');
$this->collection = $database->getCollection('phpmongo_test_collection');
}