def METHOD_NAME(self, device, device_settings):
    validated_dict = super().METHOD_NAME(device, device_settings)
    for widget, widget_settings in validated_dict.items():
        if widget_settings['action'] == "add" and widget not in self.machine.widgets:
            raise AssertionError("Unknown widget {}".format(widget))
        if widget_settings["target"] and widget_settings["target"] not in self.machine.targets:
            raise AssertionError("Unknown target {}".format(widget_settings["target"]))
    return validated_dict