Truncate sentence

#[test]
fn t1() {
    let start = std::time::Instant::now();
    let val = Solution::truncate_sentence("Hello how are you Contestant".to_string(), 4);
    let expected = "Hello how are you".to_string();
    log_result!(val == expected, "t1", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t2() {
    let start = std::time::Instant::now();
    let val = Solution::truncate_sentence("What is the solution to this problem".to_string(), 4);
    let expected = "What is the solution".to_string();
    log_result!(val == expected, "t2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t3() {
    let start = std::time::Instant::now();
    let val = Solution::truncate_sentence("chopper is not a tanuki".to_string(), 5);
    let expected = "chopper is not a tanuki".to_string();
    log_result!(val == expected, "t3", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t4() {
    let start = std::time::Instant::now();
    let val = Solution::truncate_sentence("Hello World".to_string(), 1);
    let expected = "Hello".to_string();
    log_result!(val == expected, "t4", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t5() {
    let start = std::time::Instant::now();
    let val = Solution::truncate_sentence("one two".to_string(), 2);
    let expected = "one two".to_string();
    log_result!(val == expected, "t5", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn t6() {
    let start = std::time::Instant::now();
    let val = Solution::truncate_sentence("a b c d e".to_string(), 3);
    let expected = "a b c".to_string();
    log_result!(val == expected, "t6", start, &expected, &val);
    assert_eq!(val, expected);
}