{"ast_node_type":"variable","tokens":[{"end":58,"kind":"keyword","start":0,"text":"let"}]}
    let graph = graph::CoverageGraph::from_mir(&mir_body);
    let mir_body = switchint_then_loop_else_return();
    print_coverage_graphviz("covgraph_switchint_then_loop_else_return", &mir_body, &graph);