Please don't add such _things_, if you must, look how it's done in others providers:
- https://github.com/hwi/HWIOAuthBundle/blob/master/OAuth/ResourceOwner/FoursquareResourceOwner.php#L33
- https://github.com/hwi/HWIOAuthBundle/blob/master/OAuth/ResourceOwner/FoursquareResourceOwner.php#L78-L81