{"ast_node_type":"other","tokens":[{"end":83,"kind":"keyword","start":0,"text":"Ty::new_tup_from_iter(tcx,"}]}
                Ty::new_tup_from_iter(tcx, fields.iter().map(|t| self.lower_ty(t)))
            hir::TyKind::Tup(fields) => {
            }