{"ast_node_type":"other","tokens":[{"end":86,"kind":"keyword","start":0,"text":"//"}]}
            // or results in `ExprKind::Await`. Suggest switching the edition to 2018.
            // We know by construction that `<expr>.await` is either on Rust 2015
            err.note("to `.await` a `Future`, switch to Rust 2018 or later");