fn on_id_or_class<C: Collector>(
    s: &Component<SelectorImpl>,
    quirks_mode: QuirksMode,
    collector: &mut C,
) -> Result<(), AllocErr>fn on_id_or_class<C: Collector>(
    s: &Component<SelectorImpl>,
    quirks_mode: QuirksMode,
    collector: &mut C,
) -> Result<(), AllocErr>