update deps & install rector

Behavioral/Observer/User.php

@@ -2,33 +2,30 @@
 
 namespace DesignPatterns\Behavioral\Observer;
 
+use SplSubject;
+use SplObjectStorage;
+use SplObserver;
+
 /**
  * User implements the observed object (called Subject), it maintains a list of observers and sends notifications to
  * them in case changes are made on the User object
  */
-class User implements \SplSubject
+class User implements SplSubject
 {
-    /**
-     * @var string
-     */
-    private $email;
-
-    /**
-     * @var \SplObjectStorage
-     */
-    private $observers;
+    private string $email;
+    private SplObjectStorage $observers;
 
     public function __construct()
     {
-        $this->observers = new \SplObjectStorage();
+        $this->observers = new SplObjectStorage();
     }
 
-    public function attach(\SplObserver $observer)
+    public function attach(SplObserver $observer)
     {
         $this->observers->attach($observer);
     }
 
-    public function detach(\SplObserver $observer)
+    public function detach(SplObserver $observer)
     {
         $this->observers->detach($observer);
     }
@@ -41,7 +38,7 @@ class User implements \SplSubject
 
     public function notify()
     {
-        /** @var \SplObserver $observer */
+        /** @var SplObserver $observer */
         foreach ($this->observers as $observer) {
             $observer->update($this);
         }

Behavioral/Observer/UserObserver.php

@@ -2,19 +2,18 @@
 
 namespace DesignPatterns\Behavioral\Observer;
 
+use SplObserver;
 use SplSubject;
 
-class UserObserver implements \SplObserver
+class UserObserver implements SplObserver
 {
     /**
      * @var SplSubject[]
      */
-    private $changedUsers = [];
+    private array $changedUsers = [];
 
     /**
      * It is called by the Subject, usually by SplSubject::notify()
-     *
-     * @param SplSubject $subject
      */
     public function update(SplSubject $subject)
     {