    use super::*;
    use crate::utils::test_tools::{ map_nested_to_string, map_to_string, assert_equivalent };

    #[test]
    fn test_word_squares_1() {
        let input = map_to_string(&[
            "area","lead","wall","lady","ball"
        ]);
        let output = map_nested_to_string(
            &[
                vec![ "wall",
                  "area",
                  "lead",
                  "lady"