{"ast_node_type":"variable","tokens":[{"end":79,"kind":"keyword","start":0,"text":"let"}]}
                let is_closure = if let ExprKind::Closure(closure) = arg.kind {
                // See <https://github.com/rust-lang/rust/issues/112225>.
                    !tcx.coroutine_is_async(closure.def_id.to_def_id())