Function open_interlace_with_selector 

pub async fn open_interlace_with_selector(
    peer: ConnectedPeer,
    selector: impl FnMut(Option<&PortText>) -> Option<(LaceHandle, SessionOperand)> + Send + 'static,
    operation: InterlaceOperationOptions,
) -> Result<OpenInterlace>

Open an interlace between a local Lace selector chooses, position First, and peer, position Second. Every logical session takes its operand and optional expected peer By from selector, called with the port of that session’s peer preface; the first call also chooses the Lace, which serves the whole carrier, so a later call must return it again. None, or another Lace, refuses the session as PeerProtocol. Until the first selection the operation owns the transport and its prefacing deadline but no Lace. peer must not carry an expected peer By, and the operation takes no policy replacement.