{"ast_node_type":"other","tokens":[{"end":42,"kind":"keyword","start":0,"text":"assert_eq!(graph.successors(5),"}]}
    assert_eq!(graph.successors(5), &[1]);
    assert_eq!(graph.successors(4), &[] as &[usize]);
    assert_eq!(graph.successors(6), &[] as &[usize]);