options.go
func WithNoDial(ctx context.Context, reason string) context.Context {
	return context.WithValue(ctx, noDial, reason)
}
func WithNoDial(ctx context.Context, reason string) context.Context {
	return context.WithValue(ctx, noDial, reason)
}
// WithNoDial constructs a new context with an option that instructs the network
// to not attempt a new dial when opening a stream.