{"ast_node_type":"other","tokens":[{"end":76,"kind":"keyword","start":0,"text":"assert_eq!(\"abcdefgh\","}]}
    assert_eq!("abcdefgh", format_with_underscores("abcdefgh".to_string()));
    assert_eq!("------", format_with_underscores("------".to_string()));
    assert_eq!("-1b", format_with_underscores("-1b".to_string()));