use crate::client::Capabilities;use crate::{Protocol, Service};use std::{io, net::TcpStream, path::Path}; pub struct Connection<R, W> {    _read: R,    _write: W,} impl<R, W> crate::client::Transport for Connection<R, W>where    R: io::Read,    W: io::Write,{    fn set_service(&self) -> &[&str] {        unimplemented!("cached capabilities")    }     fn command_capabilities(&self, _command: &str, _out: &mut Vec<&str>) -> bool {        unimplemented!("command capabilities")    }} impl<R, W> crate::client::TransportSketch for Connection<R, W>where    R: io::Read,    W: io::Write,{    fn set_service(        &self,        _service: Service,        _protocol: Protocol,    ) -> Result<(Capabilities, Option<Box<dyn io::BufRead>>), crate::client::Error> {        unimplemented!()    }} use quick_error::quick_error;quick_error! {    #[derive(Debug)]    pub enum Error {        Tbd {            display("tbd")        }    }} pub fn connect(    _host: &str,    _path: &Path,    _version: crate::Protocol,    _port: Option<u16>,) -> Result<Connection<TcpStream, TcpStream>, Error> {    unimplemented!("file connection")}