diff --git a/test/darkleaf/di/tutorial/z_memoize_test.clj b/test/darkleaf/di/tutorial/z_memoize_test.clj
index eee64886..e71dd9f7 100644
--- a/test/darkleaf/di/tutorial/z_memoize_test.clj
+++ b/test/darkleaf/di/tutorial/z_memoize_test.clj
@@ -34,3 +34,24 @@
     (with-open [local (di/start `root
                                 (di/use-cache cache))]
       (t/is (identical? global-system @local)))))
+
+#_
+;; or should we use external atom to also cache in local system?
+(t/deftest ok
+  (let [cache (atom {})  ;; (di/make-cache)
+        global-system (di/start `root
+                                (di/collect-cache cache))]
+
+    (with-open [local (di/start `root
+                                (di/use-cache cache)
+                                (di/collect-cache cache))]
+      (t/is (identical? @global-system @local)))))
+#_
+(t/deftest ok
+  (let [cache (atom {})  ;; (di/make-cache)
+        global-system (di/start `root
+                                (di/use-cache cache))]
+
+    (with-open [local (di/start `root
+                                (di/use-cache cache))]
+      (t/is (identical? @global-system @local)))))