{"ast_node_type":"variable","tokens":[{"end":66,"kind":"keyword","start":0,"text":"let"}]}
        let bt = ty::BoundTy { var, kind: ty::BoundTyKind::Anon };
        let var = self.canonical_var(var_kind, ty_var.into());
        Ty::new_bound(self.tcx, self.binder_index, bt)