'Route to either the user or profile table depending on which type of user
customization we are using
(profile was used in Django < 1.5, user is the new way in 1.5 and up)'

def authenticate(self, facebook_id=None, facebook_email=None):

    user_attribute = is_user_attribute('facebook_id')
    if user_attribute:
        user = self.user_authenticate(facebook_id, facebook_email)
    else:
        user = self.profile_authenticate(facebook_id, facebook_email)
    return user
