pub(crate) trait ValueRecordExt {
    // Required methods
    fn is_empty(&self) -> bool;
    fn apply(&self, ctx: &mut hb_ot_apply_context_t<'_, '_>, idx: usize) -> bool;
    fn apply_to_pos(
        &self,
        ctx: &mut hb_ot_apply_context_t<'_, '_>,
        pos: &mut GlyphPosition,
    ) -> bool;
}