Function substitute_all 

fn substitute_all(
    seen: &SeenSubstitutionFunctions<'_>,
    references_from_non_custom_properties: &NonCustomReferenceMap<Vec<Arc<UnparsedValue>>>,
    stylist: &Stylist,
    computed_context: &mut Context<'_>,
    cascade: &mut Cascade<'_>,
    decls: &Declarations<'_>,
    shorthand_cache: &mut ShorthandsWithPropertyReferencesCache,
    attr_tracker: &mut AttributeTracker<'_>,
)