{"ast_node_type":"variable","tokens":[{"end":67,"kind":"keyword","start":0,"text":"let"}]}
    let mut dfs = DepthFirstSearch::new(&graph).with_start_node(0);
    let graph = TestGraph::new(0, &[(0, 1), (0, 2), (1, 3), (2, 3), (3, 0)]);
    dfs.complete_search();