Add missing return types to magic methods

Author: wouterj

DataCollector/DataCollector.php

@@ -82,6 +82,9 @@ public function __sleep(): array
         return ['data'];
     }
 
+    /**
+     * @return void
+     */
     public function __wakeup()
     {
     }

DataCollector/DumpDataCollector.php

@@ -167,7 +167,7 @@ public function __sleep(): array
     /**
      * @internal
      */
-    public function __wakeup()
+    public function __wakeup(): void
     {
         parent::__wakeup();
 

Kernel.php

@@ -835,6 +835,9 @@ public function __sleep(): array
         return ['environment', 'debug'];
     }
 
+    /**
+     * @return void
+     */
     public function __wakeup()
     {
         if (\is_object($this->environment) || \is_object($this->debug)) {