{"ast_node_type":"variable","tokens":[{"end":42,"kind":"keyword","start":0,"text":"let"}]}
    let def_id = mir_body.source.def_id();
fn instrument_function_for_coverage<'tcx>(tcx: TyCtxt<'tcx>, mir_body: &mut mir::Body<'tcx>) {
    let _span = debug_span!("instrument_function_for_coverage", ?def_id).entered();