This setter looks like not a good idea to as it modifies the internal data structure of the `$resource` array.
It would be better to define different setter to define each of the possible configurations:
* `setCollectionName`
* `setDatabaseName`
* `setDriverOptions`
* `setConnectionOptions` (this will be the second argument of `MongoClient` - It's named `optins` in php.net but documented as `An array of options for the connection`)
* `setServer`