diff -r 56308e61381c -r 846026b8422b Twig-1.3.0/lib/Twig/Extension.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Twig-1.3.0/lib/Twig/Extension.php	Wed Oct 26 21:44:35 2011 +0200
@@ -0,0 +1,93 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) 2009 Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+abstract class Twig_Extension implements Twig_ExtensionInterface
+{
+    /**
+     * Initializes the runtime environment.
+     *
+     * This is where you can load some file that contains filter functions for instance.
+     *
+     * @param Twig_Environment $environment The current Twig_Environment instance
+     */
+    public function initRuntime(Twig_Environment $environment)
+    {
+    }
+
+    /**
+     * Returns the token parser instances to add to the existing list.
+     *
+     * @return array An array of Twig_TokenParserInterface or Twig_TokenParserBrokerInterface instances
+     */
+    public function getTokenParsers()
+    {
+        return array();
+    }
+
+    /**
+     * Returns the node visitor instances to add to the existing list.
+     *
+     * @return array An array of Twig_NodeVisitorInterface instances
+     */
+    public function getNodeVisitors()
+    {
+        return array();
+    }
+
+    /**
+     * Returns a list of filters to add to the existing list.
+     *
+     * @return array An array of filters
+     */
+    public function getFilters()
+    {
+        return array();
+    }
+
+    /**
+     * Returns a list of tests to add to the existing list.
+     *
+     * @return array An array of tests
+     */
+    public function getTests()
+    {
+        return array();
+    }
+
+    /**
+     * Returns a list of functions to add to the existing list.
+     *
+     * @return array An array of functions
+     */
+    public function getFunctions()
+    {
+        return array();
+    }
+
+    /**
+     * Returns a list of operators to add to the existing list.
+     *
+     * @return array An array of operators
+     */
+    public function getOperators()
+    {
+        return array();
+    }
+
+    /**
+     * Returns a list of global functions to add to the existing list.
+     *
+     * @return array An array of global functions
+     */
+    public function getGlobals()
+    {
+        return array();
+    }
+}