#![allow(unused_variables)]
fn main() {
    use std::collections::VecDeque;
    let mut deque: VecDeque<u32> = VecDeque::new();
    deque.push_back(0);
    deque.push_back(1);
    assert_eq!(deque.contains(& 1), true);
    assert_eq!(deque.contains(& 10), false);
}