{"ast_node_type":"other","tokens":[{"end":71,"kind":"keyword","start":0,"text":"!tcx.coroutine_is_async(closure.def_id.to_def_id())"}]}
                    !tcx.coroutine_is_async(closure.def_id.to_def_id())
                let is_closure = if let ExprKind::Closure(closure) = arg.kind {
                } else {