Python 3.9 is now generally available.

google.appengine.api.apiproxy_stub_map.MakeSyncCall

The APIProxy entry point for a synchronous API call.

service string. Represents which service to call.
call string. Represents which function to call.
request Protocol buffer for the request.
response Protocol buffer for the response.
stubmap Optional APIProxyStubMap instance, for dependency injection.

Response protocol buffer or None. Some implementations may return a response protocol buffer instead of modifying response. Caller must use returned value in such cases. If response is modified then returns None.

apiproxy_errors.Error or a subclass.