## WriteMonitor
Monitor the amount of bytes written to a [`tokio::io::AsyncWrite`](https://docs.rs/tokio/latest/tokio/io/trait.AsyncWrite.html)  
or a [`futures::io::AsyncWrite`](https://docs.rs/futures/latest/futures/io/trait.AsyncWrite.html)
or a [`std::io::Write`](https://doc.rust-lang.org/stable/std/io/trait.Write.html)