{"ast_node_type":"function","tokens":[{"end":95,"kind":"keyword","start":0,"text":"fn"}]}
    fn mark_as_used_if_union(&mut self, adt: ty::AdtDef<'tcx>, fields: &[hir::ExprField<'_>]) {
        if adt.is_union() && adt.non_enum_variant().fields.len() > 1 && adt.did().is_local() {