{"ast_node_type":"other","tokens":[{"end":35,"kind":"keyword","start":0,"text":"covspans.retain_mut(|covspan|"}]}
    covspans.retain_mut(|covspan| {
    let source_map = tcx.sess.source_map();
        let Some(span) = ensure_non_empty_span(source_map, covspan.span) else { return false };