{"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"//"}]}
        // expr is a `Block`, meaning that `{ #expr }` gets expanded
        let tcx = args.as_ref().map(|t| quote! { #t }).unwrap_or_else(|| quote! { _ });
        // to `{ { stmts... } }`, which triggers the `unused_braces` lint.