{"ast_node_type":"variable","tokens":[{"end":29,"kind":"keyword","start":0,"text":"let"}]}
        let tcx = self.tcx();
    fn maybe_suggest_impl_trait(&self, self_ty: &hir::Ty<'_>, diag: &mut Diag<'_>) -> bool {
        let parent_id = tcx.hir_get_parent_item(self_ty.hir_id).def_id;