{"ast_node_type":"variable","tokens":[{"end":33,"kind":"keyword","start":0,"text":"let"}]}
    let _: io::Result<()> = try {
    // Also dump the region constraint SCC graph as a graphviz file.
        let mut file = create_dump_file(tcx, "regioncx.scc.dot", false, "nll", &0, body)?;