Python requests retry adapter with multiple sequential requests

I have a class CustomSession. It behaves the same way as requests.Session, except calling the request method of this new class first makes a preliminary request prelim_request first using some pre-defined PRELIM_PARAMS, and then secondly makes a request request with user-provided parameters.

class CustomSession(requests.Session):    def __init__(self):        super().__init__()        self.prelim_params = PRELIM_PARAMS    def prelim_request(self):        response = super().request(**self.prelim_params)    def request(self, method, url, **kwargs):        self.prelim_request()        return super().request(method, url, **kwargs)

I want to implement some retry logic so that CustomSession.request is re-tried if the status_code of its output is either [502, 503, 504]. If I was just using the parent class requests.Session to make requests this would be done as follows:

retries = Retry(total=7, backoff_factor=1, status_forcelist=[502, 503, 504], allowed_methods=None)session.mount('http://', HTTPAdapter(max_retries=retries))session.mount('https://', HTTPAdapter(max_retries=retries))

But this only re-tries individual requests, i.e. if CustomSession.request outputs a response with status_code as 502 then only the second of the two requests within the method super().request(method, url, **kwargs) is retried, and NOT the entire CustomSession.request method itself (the two requests banded together).

I can probably resort to using try-except logic here but I would like to still use the Retry adapter if possible. How can I still make use of Retry here?