Function watcher_subscription 

pub fn watcher_subscription<T>(
    settings_daemon: CosmicSettingsDaemonProxy<'static>,
    config_id: &'static str,
    is_state: bool,
) -> Subscription<Update<T>>
where
    T: CosmicConfigEntry + Send + Sync + Default + 'static + Clone,

Available on crate features dbus and subscription only.