Python 3.9 is now generally available.

google.appengine.api.urlfetch.make_fetch_call

Executes the RPC call to fetch a given HTTP URL.

The first argument is a UserRPC instance. See urlfetch.fetch for a thorough description of the remaining arguments.

InvalidMethodError If the requested method is not in _VALID_METHODS.
ResponseTooLargeError If the response payload is too large.
InvalidURLError If there are issues with the content or size of the requested url.

The rpc object that was passed into the function.