I don't know - what is wrong, but tests failed in Bottle Song

I’ve got this message in test 2 and test 3 of bottle song:

It looks like the test runner failed to retrieve the code for this test. Please consider reporting this on the forum so we can try to fix it. Thanks!

And I don’t - how I can to improve my code:

use std::collections::HashMap;
//rust
fn capitalize_first_letter(s: &str) -> String {
    let mut chars = s.chars();
    match chars.next() {
        None => String::new(),
        Some(first) => {
            let capitalized = first.to_uppercase().collect::<String>();
            let rest = chars.collect::<String>();
            capitalized + &rest
        }
    }
}

pub fn recite(start_bottles: u32, take_down: u32) -> String {
    let mut map: HashMap<u32, &str> = HashMap::new();
    map.insert(0, "no");
    map.insert(1 ,"one");
    map.insert(2, "two");
    map.insert(3 ,"three");
    map.insert(4, "four");
    map.insert(5 ,"five");
    map.insert(6, "six");
    map.insert(7 ,"seven");
    map.insert(8, "eigth");
    map.insert(9 ,"nine");
    map.insert(10 ,"ten");
    let mut result = String::new();
    let end_bottles = start_bottles.saturating_sub(take_down - 1);
    for i in (end_bottles..=start_bottles).rev() {
        let current_bottles = capitalize_first_letter(map.get(&i).unwrap_or(&"no"));
        let next_bottles = map.get(&(i.saturating_sub(1))).unwrap_or(&"no");

        result.push_str(&format!(
            "{} green bottle{} hanging on the wall,\n",
            current_bottles,
            if i == 1 { "" } else { "s" }
        ));
        result.push_str(&format!(
            "{} green bottle{} hanging on the wall,\n",
            current_bottles,
            if i == 1 { "" } else { "s" }
        ));
        result.push_str(&format!(
            "And if one green bottle should accidentally fall,\n"
        ));
        result.push_str(&format!(
            "There'll be {} green bottle{} hanging on the wall.\n\n",
            next_bottles,
            if i == 2 { "" } else { "s" }
        ));
    }
    result.trim().to_string()
}

Thanks for the report, should be fixed by this PR.