Close GH-974: no using underscore -> no last() on collection..

labs/architecture-examples/exoskeleton/js/collections/todos.js

@@ -26,6 +26,11 @@ var app = app || {};
 			return this.where({completed: false});
 		},
 		
+		// Return last item on list if any. Otherwise return null.
+		last: function () {
+			return this.length > 0 ? this.at(this.length - 1) : null;
+		},
+
 		// We keep the Todos in sequential order, despite being saved by unordered
 		// GUID in the database. This generates the next order number for new items.
 		nextOrder: function () {