* g_dbus_interface_info_generate_xml:
* @info: A #GDBusNodeInfo
* @indent: Indentation level.
- * @string_builder: A #GString to to append XML data to.
+ * @string_builder: (out): A #GString to to append XML data to.
*
* Appends an XML representation of @info (and its children) to @string_builder.
*
* g_dbus_node_info_generate_xml:
* @info: A #GDBusNodeInfo.
* @indent: Indentation level.
- * @string_builder: A #GString to to append XML data to.
+ * @string_builder: (out): A #GString to to append XML data to.
*
* Appends an XML representation of @info (and its children) to @string_builder.
*