{"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":"hir::FnRetTy::DefaultReturn(_)"}]}
                        hir::FnRetTy::DefaultReturn(_) => None,
                    let hir_ty = match fn_decl.output {
                        hir::FnRetTy::Return(ty) => Some(ty),