}
		client.cancelFn(context.Canceled)
		c.outgoing.Delete(client.MuxID)
	}()
	return client.traceRoundtrip(ctx, c.trace, h, req)
}

// NewStream creates a new stream.
// Initial payload can be reused by the caller.
func (c *Connection) NewStream(ctx context.Context, h HandlerID, payload []byte) (st *Stream, err error) {
	if !h.valid() {
		return nil, ErrUnknownHandler
	}
	if c.State() != StateConnected {