Report network IO statistics.
You are writing a PaaS, and you need a way to bill customers based
on network and filesystem usage.
Create a wrapper for network connections and files that can report IO
statistics. The wrapper must report:
- The total number of bytes read/written.
- The total number of read/write operations.
Network and file operations are implemented in terms of the
io::Write traits. It will therefore be necessary to implement those traits for your types.