{"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"intravisit::walk_fn_ret_ty(&mut"}]}
    intravisit::walk_fn_ret_ty(&mut appears_in_output, &sig.decl.output);
        AllCollector { has_fully_capturing_opaque: false, regions: Default::default() };
    if appears_in_output.has_fully_capturing_opaque {