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: server.rs
    path of file: ./repos/tonic/examples/src/streaming
    
    the code of the file until where you have to start completion: pub mod pb {
    tonic::include_proto!("grpc.examples.echo");
}

use std::{error::Error, io::ErrorKind, net::ToSocketAddrs, pin::Pin, time
    
fn match_for_io_error(err_status: &Status) -> Option<&std::io::Error> {
    let mut err: &(dyn Error + 'static) = err_status;

    loop {
        if let Some(io_err) = err.downcast_ref::<std::io::Error>() {
            return Some(io_err);
        }

        // h2::Error do not expose std::io::Error with `source()`
        // https://github.com/hyperium/h2/pull/462
        if let Some(h2_err) = err.downcast_ref::<h2::Error>() {
            if let Some(io_err) = h2_err.get_io() {
                return Some(io_err);
            }
        }

        err = match err.source() {
            Some(err) => err,
            None => return None,
        };
    }
}