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>>,

Available on crate feature client and (crate features http1 or http2) only.

Returns a handshake future over some IO.

This is a shortcut for Builder::new().handshake(io). See client::conn for more.