{"ast_node_type":"function","tokens":[{"end":88,"kind":"keyword","start":0,"text":"fn"}]}
    fn validate_candidate(&mut self, candidate: Candidate) -> Result<(), Unpromotable> {
impl<'tcx> Validator<'_, 'tcx> {
        let Left(statement) = self.body.stmt_at(candidate.location) else { bug!() };