public function registerExtension(common_ext_Extension $extension)
    {
        $entry = array(
        	'installed' => $extension->getManifest()->getVersion(),
            'enabled' => false 
        );
        $extensions = $this->getExtensionById('generis')->getConfig(self::EXTENSIONS_CONFIG_KEY);
        $extensions[$extension->getId()] = $entry;
        return $this->getExtensionById('generis')->setConfig(self::EXTENSIONS_CONFIG_KEY, $extensions);
    }