You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: bucket_map.rs
    path of file: ./repos/solana/bucket_map/tests
    
    the code of the file until where you have to start completion: use {
    rayon::prelude::*,
    solana_bucket_map::bucket_map::{BucketMap, BucketMapConfig},
    solana_measure::measure::Measure,
    solana_sdk::pubkey::Pubkey,
    std::path::PathBuf,
};
#[test]
#[ignore]
fn bucket_map_test_mt() {
    let threads = 4096;
    let items = 4096;
    let tmpdir1 = std::env::temp_dir().join("bucket_map_test_mt");
    let tmpdir2 = PathBuf::from("/mnt/data/0").join("bucket_map_test_mt");
    let paths: Vec<PathBuf> = [tmpdir1, tmpdir2]
        .iter()
        .filter(|x| std::fs::create_dir_all(x).is_ok())
        .cloned()
        .collect();
    assert!(!paths.is_empty());
    let index = BucketMap::new(BucketMapConfig {
        max_buckets: 1 << 12,
        drives: 
    
fn bucket_map_test_mt() {
    let threads = 4096;
    let items = 4096;
    let tmpdir1 = std::env::temp_dir().join("bucket_map_test_mt");
    let tmpdir2 = PathBuf::from("/mnt/data/0").join("bucket_map_test_mt");
    let paths: Vec<PathBuf> = [tmpdir1, tmpdir2]
        .iter()
        .filter(|x| std::fs::create_dir_all(x).is_ok())
        .cloned()
        .collect();
    assert!(!paths.is_empty());
    let index = BucketMap::new(BucketMapConfig {
        max_buckets: 1 << 12,
        drives: Some(paths.clone()),
        ..BucketMapConfig::default()
    });
    (0..threads).into_par_iter().for_each(|_| {
        let key = Pubkey::new_unique();
        index.update(&key, |_| Some((vec![0u64], 0)));
    });
    let mut timer = Measure::start("bucket_map_test_mt");
    (0..threads).into_par_iter().for_each(|_| {
        for _ in 0..items {
            let key = Pubkey::new_unique();
            let ix: u64 = index.bucket_ix(&key) as u64;
            index.update(&key, |_| Some((vec![ix], 0)));
            assert_eq!(index.read_value(&key), Some((vec![ix], 0)));
        }
    });
    timer.stop();
    println!("time: {}ns per item", timer.as_ns() / (threads * items));
    let mut total = 0;
    for tmpdir in paths.iter() {
        let folder_size = fs_extra::dir::get_size(tmpdir).unwrap();
        total += folder_size;
        std::fs::remove_dir_all(tmpdir).unwrap();
    }
    println!("overhead: {}bytes per item", total / (threads * items));
}