def find_resource(controller)
      ResourcesController.raise_cant_find_singleton(name, klass) unless controller.enclosing_resource
      controller.enclosing_resource.send(source)
    end
def find_resource(controller)
      ResourcesController.raise_cant_find_singleton(name, klass) unless controller.enclosing_resource
      controller.enclosing_resource.send(source)
    end
finds the resource from the enclosing resource.  Raise CantFindSingleton if there is no enclosing resource