'Extends the expiration time of a valid OAuth access token. See
<https://developers.facebook.com/docs/facebook-login/access-tokens/
expiration-and-extension>'

def extend_access_token(self, app_id, app_secret):

    args = {'client_id': app_id, 'client_secret': app_secret, 'grant_type': 'fb_exchange_token', 'fb_exchange_token': self.access_token}
    return self.request('{0}/oauth/access_token'.format(self.version), args=args)
