Function handshake
pub async fn handshake<T, B>(io: T) -> Result<(SendRequest<B>, Connection<T, B>)>
where
T: Read + Write + Unpin,
B: Body + 'static,
B::Data: Send,
B::Error: Into<Box<dyn StdError + Send + Sync>>,
Returns a handshake future over some IO.
This is a shortcut for Builder::new().handshake(io).
See client::conn for more.