https://developers.facebook.com/docs/apps/changelog -> Changes from v2.2
to v2.3 [Oauth Access Token] Format - The response format of
https://www.facebook.com/v2.3/oauth/access_token returned when you
exchange a code for an access_token now return valid JSON instead of
being URL encoded. The new format of this response is {"access_token":
{TOKEN}, "token_type":{TYPE}, "expires_in":{TIME}}. We made this update
to be compliant with section 5.1 of RFC 6749.If I understood correctly
for version >= 2...