{"ast_node_type":"variable","tokens":[{"end":88,"kind":"keyword","start":0,"text":"let"}]}
    let fn_cov_info = tcx.instance_mir(instance.def).function_coverage_info.as_deref()?;
) -> Option<CovfunRecord<'tcx>> {
    let ids_info = tcx.coverage_ids_info(instance.def)?;