diff --git a/store2store/src/main/java/com/playmoweb/store2store/store/StoreDao.java b/store2store/src/main/java/com/playmoweb/store2store/store/StoreDao.java
index 2492961..9821c76 100644
--- a/store2store/src/main/java/com/playmoweb/store2store/store/StoreDao.java
+++ b/store2store/src/main/java/com/playmoweb/store2store/store/StoreDao.java
@@ -6,6 +6,7 @@
 import java.util.List;
 
 import io.reactivex.Flowable;
+import io.reactivex.functions.Function;
 
 /**
  * @author Thibaud Giovannetti
@@ -78,4 +79,23 @@ public Flowable<Integer> delete(final T item) {
     public Flowable<Integer> deleteAll() {
         throw new UnsupportedOperationException("This method has not been implemented in the child class");
     }
+
+    /**
+     * Wrap an object into an flowable optional
+     */
+    protected <S> Flowable<Optional<S>> wrapOptional(S obj){
+        return Flowable.just(Optional.wrap(obj));
+    }
+
+    /**
+     * Wrap a flowable object into an flowable optional
+     */
+    protected <S> Flowable<Optional<S>> wrapOptional(Flowable<S> obj){
+        return obj.flatMap(new Function<S, Flowable<Optional<S>>>() {
+            @Override
+            public Flowable<Optional<S>> apply(S s) throws Exception {
+                return wrapOptional(s);
+            }
+        });
+    }
 }
diff --git a/store2store/src/main/java/com/playmoweb/store2store/store/StoreService.java b/store2store/src/main/java/com/playmoweb/store2store/store/StoreService.java
index 5f94f1a..53a9055 100644
--- a/store2store/src/main/java/com/playmoweb/store2store/store/StoreService.java
+++ b/store2store/src/main/java/com/playmoweb/store2store/store/StoreService.java
@@ -591,23 +591,4 @@ public Flowable<Integer> apply(Optional<T> reinsertedItem) throws Exception {
         flowables.add(flowStorage);
         return Flowable.concat(flowables);
     }
-
-    /**
-     * Wrap an object into an flowable optional
-     */
-    public <S> Flowable<Optional<S>> wrapOptional(S obj){
-        return Flowable.just(Optional.wrap(obj));
-    }
-
-    /**
-     * Wrap a flowable object into an flowable optional
-     */
-    public <S> Flowable<Optional<S>> wrapOptional(Flowable<S> obj){
-        return obj.flatMap(new Function<S, Flowable<Optional<S>>>() {
-            @Override
-            public Flowable<Optional<S>> apply(S s) throws Exception {
-                return wrapOptional(s);
-            }
-        });
-    }
 }