Fix some minor code quality issues

Author: teohhanhui

src/GraphQl/Resolver/ResourceAccessCheckerTrait.php

@@ -11,15 +11,6 @@
 
 declare(strict_types=1);
 
-/*
- * This file is part of the API Platform project.
- *
- * (c) Kévin Dunglas <[email protected]>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
 namespace ApiPlatform\Core\GraphQl\Resolver;
 
 use ApiPlatform\Core\Metadata\Resource\ResourceMetadata;

src/Security/ResourceAccessChecker.php

@@ -11,15 +11,6 @@
 
 declare(strict_types=1);
 
-/*
- * This file is part of the API Platform project.
- *
- * (c) Kévin Dunglas <[email protected]>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
 namespace ApiPlatform\Core\Security;
 
 use ApiPlatform\Core\Util\ClassInfoTrait;

src/Serializer/ResourceList.php

@@ -18,7 +18,11 @@
  */
 class ResourceList extends \ArrayObject
 {
-    public function serialize()
+    /**
+     * {@inheritdoc}
+     */
+    public function serialize(): ?string
     {
+        return null;
     }
 }

tests/Fixtures/Query.php

@@ -18,11 +18,13 @@
  */
 class Query
 {
-    public function getFirstResult()
+    public function getFirstResult(): ?int
     {
+        return null;
     }
 
-    public function getMaxResults()
+    public function getMaxResults(): ?int
     {
+        return null;
     }
 }