let (_, s1) = s1.split_at(1);

                    let (_, s1) = s1.split_at(1);

                    let (_, s1) = s1.split_at(1);

                    let (_, s1) = s1.split_at(1);

}
#[test]
pub fn del_leaf() {
    env_logger::try_init().unwrap_or(());
    let env = Env::new_anon(409600000, 1).unwrap();
    let mut txn = Env::mut_txn_begin(&env).unwrap();
    let mut db: Db<u64, u64> = create_db(&mut txn).unwrap();
    let n = 20 as u64;
    let i0 = 10 as u64;
    let mut values = Vec::with_capacity(n as usize);
    for i in 0..n {
        put(&mut txn, &mut db, &i, &i).unwrap();
        if i != i0 {
            values.push(i);
        }
    }
    let db2 = fork_db(&mut txn, &db).unwrap();
    del(&mut txn, &mut db, &i0, None).unwrap();
    assert_eq!(
        btree::iter(&txn, &db, None)
            .unwrap()
            .map(|kv| *kv.unwrap().0)
            .collect::<Vec<_>>(),
        values
    );