{"ast_node_type":"function","tokens":[{"end":89,"kind":"keyword","start":0,"text":"fn"}]}
    fn should_warn_about_field(&mut self, field: &ty::FieldDef) -> ShouldWarnAboutField {
impl<'tcx> DeadVisitor<'tcx> {
        if self.live_symbols.contains(&field.did.expect_local()) {