diff --git a/Model/ProductManager.php b/Model/ProductManager.php
index <HASH>..<HASH> 100644
--- a/Model/ProductManager.php
+++ b/Model/ProductManager.php
@@ -32,6 +32,20 @@ abstract class ProductManager implements ProductManagerInterface
      */
     public function addIdentifierSetToProduct(ProductIdentifierSetInterface $identifierSet, ProductInterface &$product)
     {
+        $index = $this->getIdentifierSetIndex($identifierSet);
+        $product->addIdentifierSet($index, $identifierSet);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function removeIdentifierSetFromProduct($identifierSet, ProductInterface $product)
+    {
+
+    }
+
+    protected function getIdentifierSetIndex($identifierSet)
+    {
         $primaryIdentifier = $this->getPrimaryIdentifier();
         foreach ($identifierSet->getIdentifiers() as $node) {
             if ($node instanceof $primaryIdentifier) {
@@ -43,15 +57,6 @@ abstract class ProductManager implements ProductManagerInterface
                 'The primary identifier is not in this Vespolina\ProductBundle\Node\ProductIdentifierSet'
             );
         }
-        $product->addIdentifierSet($index, $identifierSet);
+        return $index;
     }
-
-    /**
-     * @inheritdoc
-     */
-    public function removeIdentifierSetFromProduct($identifierSet, ProductInterface $product)
-    {
-
-    }
-
 }
refactor getting index for identifierSet into is own method