#![allow(dead_code, deprecated, unused_variables, unused_mut)]
use std::iter;
fn main() {
    let mut four_fours = iter::repeat(4).take(4);
    assert_eq!(Some(4), four_fours.next());
    assert_eq!(Some(4), four_fours.next());
    assert_eq!(Some(4), four_fours.next());
    assert_eq!(Some(4), four_fours.next());
    assert_eq!(None, four_fours.next());
}