subscriptions/views/join.py

@@ -115,11 +115,10 @@ class JoinView(LoginRequiredMixin, FormView):
             logger_args = [self.customer.pk, gateway]
             logger.debug('Creating a new subscription for customer pk=%s, %s', *logger_args)
         collection_method = self.plan_variation.collection_method
-        supported = set(gateway.provider.supported_collection_methods)
-        if collection_method not in supported:
+        if collection_method not in gateway.provider.supported_collection_methods:
             # FIXME(anna): this breaks plan selector because collection method
             # might not match the one selected by the customer.
-            collection_method = supported.pop()
+            collection_method = next(iter(gateway.provider.supported_collection_methods))
 
         with transaction.atomic():
             subscription.plan = self.plan_variation.plan