diff -r 000000000000 -r 6474c204b198 addon-sdk/source/lib/sdk/ui/sidebar/namespace.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/addon-sdk/source/lib/sdk/ui/sidebar/namespace.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+'use strict';
+
+const models = exports.models = new WeakMap();
+const views = exports.views = new WeakMap();
+exports.buttons = new WeakMap();
+
+exports.viewsFor = function viewsFor(sidebar) views.get(sidebar);
+exports.modelFor = function modelFor(sidebar) models.get(sidebar);