diff -r 000000000000 -r 7f95f8617b0b vendor/symfony/src/Symfony/Component/Config/Definition/Builder/BooleanNodeDefinition.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/symfony/src/Symfony/Component/Config/Definition/Builder/BooleanNodeDefinition.php	Sat Sep 24 15:40:41 2011 +0200
@@ -0,0 +1,43 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Config\Definition\Builder;
+
+use Symfony\Component\Config\Definition\BooleanNode;
+
+/**
+ * This class provides a fluent interface for defining a node.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class BooleanNodeDefinition extends ScalarNodeDefinition
+{
+    /**
+     * {@inheritDoc}
+     */
+    public function __construct($name, NodeParentInterface $parent = null)
+    {
+        parent::__construct($name, $parent);
+
+        $this->nullEquivalent = true;
+    }
+
+    /**
+     * Instantiate a Node
+     *
+     * @return BooleanNode The node
+     */
+    protected function instantiateNode()
+    {
+        return new BooleanNode($this->name, $this->parent);
+    }
+
+}