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: tracked.rs
    path of file: ./repos/s2n-quic/quic/s2n-quic-core/src/buffer/reader/storage
    
    the code of the file until where you have to start completion: // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

use crate::buffer::{
    reader::{Reader, Storage},
    writer,
};

pub struct Tracked<'a, S: Storage + ?Sized> {
    consumed: usize,
    storage: &'a mut S,
}

impl<'a, S: Storage + ?Sized> Tracked<'a, S> {
    #[inline]
    pub fn new(storage: &'a mut S) -> Self {
        Self {
            consumed: 0,
            storage,
        }
    }

    #[inline]
    pub fn consumed_len(&self) -> usize {
        self.consumed
    }
}

impl<'a, S: Storage + ?Sized> Storage for Tracked<'a, S> {
    type Error = S::Error
    
    fn tracked_test() {
        let mut reader = &b"hello world"[..];
        let mut writer: Vec<u8> = vec![];

        {
            let mut reader = reader.track_read();
            let chunk = reader.read_chunk(1).unwrap();
            assert_eq!(&chunk[..], b"h");
            assert_eq!(reader.consumed_len(), 1);
        }

        {
            let mut reader = reader.track_read();
            let mut writer = writer.with_write_limit(5);

            let chunk = reader.partial_copy_into(&mut writer).unwrap();
            assert_eq!(&chunk[..], b"ello ");
            assert_eq!(reader.consumed_len(), 5);
        }

        assert_eq!(writer.len(), 0);

        {
            let mut reader = reader.track_read();
            reader.copy_into(&mut writer).unwrap();
            assert_eq!(reader.consumed_len(), 5);
            assert_eq!(&writer[..], b"world");
        }

        assert_eq!(reader.len(), 0);
    }