Use internal function to appease olddeps test

tests/state/test_v21.py

@@ -383,24 +383,30 @@ class StateResV21TestCase(unittest.HomeserverTestCase):
         room_id = events[0].room_id
         # First we try everything in-memory to check that the test case works.
         event_map = {ev.event_id: ev for ev in events}
-        resolution = self.successResultOf(
-            resolve_events_with_store(
-                FakeClock(),
-                room_id,
-                events[0].room_version,
-                state_maps,
-                event_map=event_map,
-                state_res_store=TestStateResolutionStore(event_map),
+        for ev in events:
+            print(f"{ev.event_id} => {ev.type} {ev.state_key} => {ev.content}")
+        resolution = self.get_success(
+            defer.ensureDeferred(
+                resolve_events_with_store(
+                    FakeClock(),
+                    room_id,
+                    events[0].room_version,
+                    state_maps,
+                    event_map=event_map,
+                    state_res_store=TestStateResolutionStore(event_map),
+                )
             )
         )
         self.assertEqual(resolution, expected)
 
-        got_auth_diff = self.successResultOf(
-            self._get_auth_difference_and_conflicted_subgraph(
-                room_id,
-                state_maps,
-                event_map,
-                TestStateResolutionStore(event_map),
+        got_auth_diff = self.get_success(
+            defer.ensureDeferred(
+                self._get_auth_difference_and_conflicted_subgraph(
+                    room_id,
+                    state_maps,
+                    event_map,
+                    TestStateResolutionStore(event_map),
+                )
             )
         )
         # we should never see the create event in the auth diff. If we do, this implies the