let input = vec!["nail", "shoe"];
    let expected = vec![
        "For want of a nail the shoe was lost.",
        "And all for the want of a nail.",
    ]
    .join("\n");
    assert_eq!(build_proverb(&input), expected);

	let input = vec!["nail", "shoe"];
	let expected = vec![
		"For want of a nail the shoe was lost.",
		"And all for the want of a nail.",
	]
	.join("\n");
	assert_eq!(build_proverb(&input), expected);

    let input = vec!["nail", "shoe", "horse"];
    let expected = vec![
        "For want of a nail the shoe was lost.",
        "For want of a shoe the horse was lost.",
        "And all for the want of a nail.",
    ]
    .join("\n");
    assert_eq!(build_proverb(&input), expected);

	let input = vec!["nail", "shoe", "horse"];
	let expected = vec![
		"For want of a nail the shoe was lost.",
		"For want of a shoe the horse was lost.",
		"And all for the want of a nail.",
	]
	.join("\n");
	assert_eq!(build_proverb(&input), expected);

    let input = vec!["nail"];
    let expected = String::from("And all for the want of a nail.");
    assert_eq!(build_proverb(&input), expected);

	let input = vec!["nail"];
	let expected = String::from("And all for the want of a nail.");
	assert_eq!(build_proverb(&input), expected);

    let input: Vec<&str> = vec![];
    let expected = String::new();
    assert_eq!(build_proverb(&input), expected);

	let input: Vec<&str> = vec![];
	let expected = String::new();
	assert_eq!(build_proverb(&input), expected);

    let input = vec![
        "nail", "shoe", "horse", "rider", "message", "battle", "kingdom",
    ];
    let expected = vec![
        "For want of a nail the shoe was lost.",
        "For want of a shoe the horse was lost.",
        "For want of a horse the rider was lost.",
        "For want of a rider the message was lost.",
        "For want of a message the battle was lost.",
        "For want of a battle the kingdom was lost.",
        "And all for the want of a nail.",
    ]
    .join("\n");
    assert_eq!(build_proverb(&input), expected);

	let input = vec![
		"nail", "shoe", "horse", "rider", "message", "battle", "kingdom",
	];
	let expected = vec![
		"For want of a nail the shoe was lost.",
		"For want of a shoe the horse was lost.",
		"For want of a horse the rider was lost.",
		"For want of a rider the message was lost.",
		"For want of a message the battle was lost.",
		"For want of a battle the kingdom was lost.",
		"And all for the want of a nail.",
	]
	.join("\n");
	assert_eq!(build_proverb(&input), expected);

    let input = vec!["pin", "gun", "soldier", "battle"];
    let expected = vec![
        "For want of a pin the gun was lost.",
        "For want of a gun the soldier was lost.",
        "For want of a soldier the battle was lost.",
        "And all for the want of a pin.",
    ]
    .join("\n");
    assert_eq!(build_proverb(&input), expected);

	let input = vec!["pin", "gun", "soldier", "battle"];
	let expected = vec![
		"For want of a pin the gun was lost.",
		"For want of a gun the soldier was lost.",
		"For want of a soldier the battle was lost.",
		"And all for the want of a pin.",
	]
	.join("\n");
	assert_eq!(build_proverb(&input), expected);

    unimplemented!("build a proverb from this list of items: {:?}", list)

	match list.first() {
		Some(first) => list
			.windows(2)
			.map(|window| format!("For want of a {} the {} was lost.\n", window[0], window[1]))
			.chain(std::iter::once(format!(
				"And all for the want of a {}.",
				first
			)))
			.collect(),
		_ => String::new(),
	}