diff --git a/core/Extension.php b/core/Extension.php
index 89e0b17a7..deb5b1b91 100644
--- a/core/Extension.php
+++ b/core/Extension.php
@@ -1,7 +1,12 @@
 <?php
 /**
- * Add extension that can be added to an object with Object::add_extension().
- * For DataObject extensions, use DataObjectDecorator
+ * Add extension that can be added to an object with {@link Object::add_extension()}.
+ * For {@link DataObject} extensions, use {@link DataObjectDecorator}.
+ * Each extension instance has an "owner" instance, accessible through
+ * {@link getOwner()}.
+ * Every object instance gets its own set of extension instances,
+ * meaning you can set parameters specific to the "owner instance"
+ * in new Extension instances.
  *
  * @package sapphire
  * @subpackage core
@@ -35,6 +40,19 @@ abstract class Extension extends Object {
 	public function getOwner() {
 		return $this->owner;
 	}
+	
+	/**
+	 * Helper method to strip eval'ed arguments from a string
+	 * thats passed to {@link DataObject::$extensions} or 
+	 * {@link Object::add_extension()}.
+	 * 
+	 * @param string $extensionStr E.g. "Versioned('Stage','Live')"
+	 * @return string Extension classname, e.g. "Versioned"
+	 */
+	public static function get_classname_without_arguments($extensionStr) {
+		return (($p = strpos($extensionStr, '(')) !== false) ? substr($extensionStr, 0, $p) : $extensionStr;
+	}
+	
 }
 
 ?>
\ No newline at end of file