diff -r 000000000000 -r 7f95f8617b0b vendor/symfony/src/Symfony/Component/Config/Definition/Builder/MergeBuilder.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/symfony/src/Symfony/Component/Config/Definition/Builder/MergeBuilder.php	Sat Sep 24 15:40:41 2011 +0200
@@ -0,0 +1,73 @@
+<?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;
+
+/**
+ * This class builds merge conditions.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class MergeBuilder
+{
+    protected $node;
+    public $allowFalse;
+    public $allowOverwrite;
+
+    /**
+     * Constructor
+     *
+     * @param NodeDefinition $node The related node
+     */
+    public function __construct(NodeDefinition $node)
+    {
+        $this->node = $node;
+        $this->allowFalse = false;
+        $this->allowOverwrite = true;
+    }
+
+    /**
+     * Sets whether the node can be unset.
+     *
+     * @param Boolean $allow
+     * @return MergeBuilder
+     */
+    public function allowUnset($allow = true)
+    {
+        $this->allowFalse = $allow;
+
+        return $this;
+    }
+
+    /**
+     * Sets whether the node can be overwritten.
+     *
+     * @param Boolean $deny Whether the overwriting is forbidden or not
+     *
+     * @return MergeBuilder
+     */
+    public function denyOverwrite($deny = true)
+    {
+        $this->allowOverwrite = !$deny;
+
+        return $this;
+    }
+
+    /**
+     * Returns the related node.
+     *
+     * @return NodeDefinition
+     */
+    public function end()
+    {
+        return $this->node;
+    }
+}