如何在rust中生成随机unicode字符串？

use rand::Rng;

fn generate_random_unicode_string(length: usize) -> String {
    let mut rng = rand::thread_rng();
    let unicode_chars: Vec<char> = (0..length)
        .map(|_| rng.gen_range(0x4E00..=0x9FFF) as u32)
        .map(std::char::from_u32)
        .flatten()
        .collect();
    unicode_chars.into_iter().collect()
}

fn main() {
    let random_string = generate_random_unicode_string(10);
    println!("{}", random_string);
}