diff --git a/src/darkleaf/di/core.clj b/src/darkleaf/di/core.clj
index e18ea180..66363616 100644
--- a/src/darkleaf/di/core.clj
+++ b/src/darkleaf/di/core.clj
@@ -760,38 +760,28 @@
             (demolish [_ _])))
         (registry key)))))
 
-
-;; should a cache key be the one?
 (defn collect-cache []
-  (let [cache (atom {})]
+  (let [cache (volatile! {})]
     (fn [registry]
       (fn [key]
         (if (= ::cache key)
-          cache
-          #_
-          (reify p/Factory
-            (dependencies [_]
-              nil)
-            (build [_ _]
-              cache)
-            (demolish [_ obj]
-              ;; invalidate cache if the global/main system has been stopped
-              (reset! cache {})))
+          @cache
           (let [factory (registry key)]
             (reify p/Factory
               (dependencies [_]
                 (p/dependencies factory))
               (build [_ deps]
                 (let [obj (p/build factory deps)]
-
-                  ;; тут идея в том, что если в локальной системе что-то переопределить,
-                  ;; то все, что от этого зависит - инвалидируется
-
-                  (swap! cache assoc [key deps] obj)
+                  (vswap! cache assoc
+                          [:key+deps key deps] obj
+                          #_#_
+                          [:key+obj  key obj]  true)
                   obj))
               (demolish [_ obj]
                 (p/demolish factory obj)))))))))
 
+;; может быть сделать 2 арности вместо этих 2х функций?
+
 (defn use-cache [cache]
   (fn [registry]
     (fn [key]
@@ -800,7 +790,7 @@
           (dependencies [_]
             (p/dependencies factory))
           (build [_ deps]
-            (?? (get @cache [key deps])
+            (?? (get cache [:key+deps key deps])
                 (p/build factory deps)))
           (demolish [_ obj]
             ;; todo
@@ -813,4 +803,9 @@
             ;; (swap! cache update :direct assoc [key deps] obj)
             ;; (swap! cache update :indirect conj [key obj]) ;; #{set}
 
+            ;; или можно каждой фабрике сделать локальный (volatile! cached?)
+            ;; и спрашивать у него
+            ;; но это логику di ломает
+
+
             #_"we must stop only not cached obj"))))))
diff --git a/test/darkleaf/di/tutorial/z_memoize_test.clj b/test/darkleaf/di/tutorial/z_memoize_test.clj
index e71dd9f7..3dc70c1a 100644
--- a/test/darkleaf/di/tutorial/z_memoize_test.clj
+++ b/test/darkleaf/di/tutorial/z_memoize_test.clj
@@ -5,7 +5,7 @@
 
 (defn connection
   {::di/stop #(reset! % :stopped)}
-  []
+  [{url "CONNECTION_URL"}]
   (atom :started))
 
 (defn migrations
@@ -24,34 +24,34 @@
 
 ;; todo: check registry placement
 
+(t/deftest ok
+  (let [[global-system cache :as root]
+        (di/start [`root ::di/cache]
+                  {"CONNECTION_URL" "1"}
+                  (di/collect-cache))]
 
-;; todo: test a cache reset after the global system stop
 
-(t/deftest ok
-  (let [[global-system cache] (di/start [`root ::di/cache]
-                                        (di/collect-cache))]
-    ;; cache is not printable O_o
+    (prn cache)
+
     (with-open [local (di/start `root
                                 (di/use-cache cache))]
-      (t/is (identical? global-system @local)))))
+      (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)
+                                {"CONNECTION_URL" "1"})]
+      (t/is (identical? global-system @local)))
 
     (with-open [local (di/start `root
+                                ;; `use-cache` should be the first registry
                                 (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))]
+                                {"CONNECTION_URL" "2"})]
+      (t/is (not (identical? global-system @local))))
+
+
+    #_#_
+    (di/stop root)
 
     (with-open [local (di/start `root
                                 (di/use-cache cache))]
-      (t/is (identical? @global-system @local)))))
+      (t/is (identical? global-system @local)))))