use black_red::RBTree;

let mut tree = RBTree::new();
assert!(tree.is_empty());
assert_eq!(tree.len(), 0);

for i in [5, 3, 7, 9, 6] {
    tree.insert(i);
}

assert_eq!(tree.len(), 5);
assert!(!tree.is_empty());
assert!(tree.contains(&7));
assert!(tree.remove(&7));
assert!(!tree.contains(&7));
assert!(tree.iter().eq(&[3, 5, 6, 9]));