@Override
    public final Mono<Void> writeAndFlushWith(Publisher<? extends Publisher<? extends DataBuffer>> body) {
        return new ChannelSendOperator<>(body, inner -> doCommit(() -> writeAndFlushWithInternal(inner)))
                .doOnError(t -> getHeaders().clearContentHeaders());
    }
Return the underlying server response.

<p><strong>Note:</strong> This is exposed mainly for internal framework
use such as WebSocket upgrades in the spring-webflux module.
spring/boot3-webflux-autoconfigure/src/main/java/com/linecorp/armeria/spring/web/reactive/AbstractServerHttpResponse.java