String user = config.get("user");
String password = config.get("password");
MongoClientOptions clientOptions = getClientOptions();
if (user != null && password != null) {
MongoCredential credential = MongoCredential.createMongoCRCredential(user, dbName, password.toCharArray());
client = new MongoClient(new ServerAddress(host, port), Collections.singletonList(credential), clientOptions);
} else {
client = new MongoClient(new ServerAddress(host, port), clientOptions);
}