{"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"assert_eq!(\"0\","}]}
    assert_eq!("0", format_with_underscores("0".to_string()));
    assert_eq!("", format_with_underscores("".to_string()));
    assert_eq!("12_345.67e14", format_with_underscores("12345.67e14".to_string()));