Update src/graphql/utilities/type_info.py

Co-authored-by: Syrus Akbary <me@syrusakbary.com>

Author: alexchamberlain

src/graphql/utilities/type_info.py

@@ -148,12 +148,10 @@ def leave(self, node: Node) -> None:
 
     def _get_method(self, direction: str, kind: str) -> Optional[Callable[[], None]]:
         key = (direction, kind)
-        if key in self._visit_fns:
-            return self._visit_fns[key]
-
-        fn = getattr(self, f"{direction}_{kind}", None)
-        self._visit_fns[key] = fn
-        return fn
+        if key not in self._visit_fns:
+            fn = getattr(self, f"{direction}_{kind}", None)
+            self._visit_fns[key] = fn
+        return self._visit_fns[key]
 
 
     # noinspection PyUnusedLocal