[Form] Removing unused private property and adding PHPDoc

src/Symfony/Component/Form/Extension/Core/CoreExtension.php

@@ -16,12 +16,15 @@ use Symfony\Component\Form\AbstractExtension;
 use Symfony\Component\Validator\ValidatorInterface;
 use Symfony\Component\HttpFoundation\File\TemporaryStorage;
 
+/**
+ * Represents the main form extension, which loads the core functionality.
+ *
+ * @author Bernhard Schussek <bernhard.schussek@symfony.com>
+ */
 class CoreExtension extends AbstractExtension
 {
     private $storage;
 
-    private $typeGuesser;
-
     public function __construct(TemporaryStorage $storage)
     {
         $this->storage = $storage;