Concatenate array with reverse

#[test]
fn all_same() {
    let start = std::time::Instant::now();
    let val = Solution::concat_with_reverse(vec![4, 4, 4]);
    let expected = vec![4, 4, 4, 4, 4, 4];
    log_result!(val == expected, "all_same", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn example1() {
    let start = std::time::Instant::now();
    let val = Solution::concat_with_reverse(vec![1, 2, 3]);
    let expected = vec![1, 2, 3, 3, 2, 1];
    log_result!(val == expected, "example1", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn example2() {
    let start = std::time::Instant::now();
    let val = Solution::concat_with_reverse(vec![1]);
    let expected = vec![1, 1];
    log_result!(val == expected, "example2", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn palindrome() {
    let start = std::time::Instant::now();
    let val = Solution::concat_with_reverse(vec![1, 2, 1]);
    let expected = vec![1, 2, 1, 1, 2, 1];
    log_result!(val == expected, "palindrome", start, &expected, &val);
    assert_eq!(val, expected);
}

#[test]
fn two_elements() {
    let start = std::time::Instant::now();
    let val = Solution::concat_with_reverse(vec![5, 7]);
    let expected = vec![5, 7, 7, 5];
    log_result!(val == expected, "two_elements", start, &expected, &val);
    assert_eq!(val, expected);
}