Oubli d'un retour de méthode

src/Entity/User.php

@@ -202,7 +202,7 @@ class User implements UserInterface,PasswordAuthenticatedUserInterface
         return $this->tokenValidity;
     }
 
-    private function setTokenValidity(\DateTimeInterface $tokenValidity)
+    private function setTokenValidity(\DateTimeInterface $tokenValidity): self
     {
         $this->tokenValidity = $tokenValidity;