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Spring WebFlux：仅允许一个连接接收订阅者。

spring-bootkotlinproject-reactorspring-webfluxreactor-netty
12

我正在使用Spring 5 Webflux和Kotlin编写一个简单的应用程序。我尝试以下面的方式实现PUT终点：

PUT("/confs/{id}", {
    val id = it.pathVariable("id")
    ServerResponse.ok().body(service.save(it.bodyToMono(Item::class.java)), Item::class.java)
})

保存的技巧在于我尝试从项目中读取城市名称，解析地理坐标，将它们覆盖到原始项目中，然后使用Spring Data Mongo Reactive repo保存到Mongo中。

fun save(item: Mono<Item>): Mono<Item> {
    val geo = item.flatMap {
            val city = it.location?.city ?: "Somewhere"
            geoService.resolveGeoFromCity(city)
    }

    val zipped = item.zipWith(geo)
        .map {
            it.t1.location?.geo = it.t2
            it.t1
        }

    return repo.saveAll(zipped)
        .toMono()
}

解析地理坐标的代码在这里：

@Service
class GeoService() {

    val client = WebClient.create("https://maps.googleapis.com/maps/api/geocode/")

    fun resolveGeoFromCity(city: String): Mono<Geo> {
        return client.get()
                .uri("json?address=$city&key=$API_KEY&language=en")
                .exchange()
                .flatMap { it.bodyToMono(String::class.java) }
                .map { parse(it) }
    }

    private fun parse(response: String): Geo {
        val locationMap = JsonPath.read<Map<String, Double>>(response, "$.results[0].geometry.location")
        return Geo(locationMap["lat"] ?: 0.0, locationMap["lng"] ?: 0.0)
    }

}

问题在于，如果我发送一个PUT请求，我会得到下面的堆栈跟踪。 我已经尝试使用 val geo = Mono.just(Geo(0.0, 0.0))（而不使用WebClient）来模拟Mono，并且这样做可以正常工作。

如何修复这个问题，而不损失功能？

    2018-01-01 01:41:00.595 ERROR 15120 --- [ctor-http-nio-4] .a.w.r.e.DefaultErrorWebExceptionHandler : Failed to handle request [PUT http://localhost:8097/confs/5a49675c910d123b1057207a]

    java.lang.IllegalStateException: Only one connection receive subscriber allowed.
        at reactor.ipc.netty.channel.FluxReceive.startReceiver(FluxReceive.java:276) ~[reactor-netty-0.7.2.RELEASE.jar:0.7.2.RELEASE]
        at reactor.ipc.netty.channel.FluxReceive.subscribe(FluxReceive.java:124) ~[reactor-netty-0.7.2.RELEASE.jar:0.7.2.RELEASE]
        at reactor.core.publisher.FluxMap.subscribe(FluxMap.java:62) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:252) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.ipc.netty.ByteBufFlux.subscribe(ByteBufFlux.java:242) ~[reactor-netty-0.7.2.RELEASE.jar:0.7.2.RELEASE]
        at reactor.core.publisher.FluxPeek.subscribe(FluxPeek.java:83) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:252) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.ipc.netty.ByteBufFlux.subscribe(ByteBufFlux.java:242) ~[reactor-netty-0.7.2.RELEASE.jar:0.7.2.RELEASE]
        at reactor.core.publisher.FluxMap.subscribe(FluxMap.java:62) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:252) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxFlatMap.subscribe(FluxFlatMap.java:97) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:252) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxDoFinallyFuseable.subscribe(FluxDoFinallyFuseable.java:48) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:252) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxMapFuseable.subscribe(FluxMapFuseable.java:63) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.FluxOnAssembly.subscribe(FluxOnAssembly.java:252) ~
[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoPeekTerminal.subscribe(MonoPeekTerminal.java:61) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoPeekFuseable.subscribe(MonoPeekFuseable.java:74) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.Mono.subscribe(Mono.java:3008) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:167) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:71) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoPeekTerminal.subscribe(MonoPeekTerminal.java:61) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.core.publisher.MonoOnAssembly.subscribe(MonoOnAssembly.java:76) ~[reactor-core-3.1.2.RELEASE.jar:3.1.2.RELEASE]
        at reactor.ipc.netty.channel.ChannelOperations.applyHandler(ChannelOperations.java:383) ~[reactor-netty-0.7.2.RELEASE.jar:0.7.2.RELEASE]
        at reactor.ipc.netty.http.server.HttpServerOperations.onHandlerStart(HttpServerOperations.java:359) ~[reactor-netty-0.7.2.RELEASE.jar:0.7.2.RELEASE]
        at io.netty.util.concurrent.AbstractEventExecutor.safeExecute$$$capture(AbstractEventExecutor.java:163) ~[netty-common-4.1.17.Final.jar:4.1.17.Final]
        at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java) ~[netty-common-4.1.17.Final.jar:4.1.17.Final]
        at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:403) ~[netty-common-4.1.17.Final.jar:4.1.17.Final]
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:463) ~[netty-transport-4.1.17.Final.jar:4.1.17.Final]
        at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) ~[netty-common-4.1.17.Final.jar:4.1.17.Final]
        at java.lang.Thread.run(Thread.java:745) ~[na:1.8.0_112]
        Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
    Assembly trace from producer [reactor.core.publisher.FluxMap] :
        reactor.core.publisher.Flux.map(Flux.java:4855)
        reactor.ipc.netty.ByteBufFlux.fromInbound(ByteBufFlux.java:68)
        reactor.ipc.netty.NettyInbound.receive(NettyInbound.java:90)
        org.springframework.http.server.reactive.ReactorServerHttpRequest.getBody(ReactorServerHttpRequest.java:148)
        org.springframework.http.codec.DecoderHttpMessageReader.readMono(DecoderHttpMessageReader.java:93)
        org.springframework.http.codec.DecoderHttpMessageReader.readMono(DecoderHttpMessageReader.java:123)
        org.springframework.web.reactive.function.BodyExtractors.lambda$null$0(BodyExtractors.java:101)
        java.util.Optional.map(Optional.java:215)
        org.springframework.web.reactive.function.BodyExtractors.readWithMessageReaders(BodyExtractors.java:256)
        org.springframework.web.reactive.function.BodyExtractors.lambda$toMono$2(BodyExtractors.java:96)
        org.springframework.web.reactive.function.server.DefaultServerRequest.body(DefaultServerRequest.java:126)
        org.springframework.web.reactive.function.server.DefaultServerRequest.body(DefaultServerRequest.java:120)
        org.springframework.web.reactive.function.server.DefaultServerRequest.bodyToMono(DefaultServerRequest.java:145)
        com.example.confs.web.ConferenceRouter$routes$1$2.invoke(ConferenceRouter.kt:31)
        com.example.confs.web.ConferenceRouter$routes$1$2.invoke(ConferenceRouter.kt:16)
        org.springframework.web.reactive.function.server.RouterFunctionDsl$PUT$1.handle(RouterFunctionDsl.kt:200)
        org.springframework.web.reactive.function.server.support.HandlerFunctionAdapter.handle(HandlerFunctionAdapter.java:61)
        org.springframework.web.reactive.DispatcherHandler.invokeHandler(DispatcherHandler.java:168)
        org.springframework.web.reactive.DispatcherHandler.lambda$handle$1(DispatcherHandler.java:160)
        reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:118)
        reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67)
        reactor.core.publisher.MonoNext$NextSubscriber.onNext(MonoNext.java:76)
        reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.innerNext(FluxConcatMap.java:271)
        reactor.core.publisher.FluxConcatMap$ConcatMapInner.onNext(FluxConcatMap.java:803)
        reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:115)
        reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67)
        reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67)
        reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67)
        reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onNext(FluxSwitchIfEmpty.java:67)
        reactor.core.publisher.Operators$ScalarSubscription.request(Operators.java:1649)
        reactor.core.publisher.Operators$MultiSubscriptionSubscriber.set(Operators.java:1463)
        reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onSubscribe(Operators.java:1337)
        reactor.core.publisher.MonoJust.subscribe(MonoJust.java:54)
        reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
        reactor.core.publisher.Mono.subscribe(Mono.java:3008)
        reactor.core.publisher.FluxSwitchIfEmpty$SwitchIfEmptySubscriber.onComplete(FluxSwitchIfEmpty.java:75)
        reactor.core.publisher.Operators.complete(Operators.java:125)
        reactor.core.publisher.MonoEmpty.subscribe(MonoEmpty.java:45)
        reactor.core.publisher.MonoSwitchIfEmpty.subscribe(MonoSwitchIfEmpty.java:44)
        reactor.core.publisher.MonoSwitchIfEmpty.subscribe(MonoSwitchIfEmpty.java:44)
        reactor.core.publisher.MonoSwitchIfEmpty.subscribe(MonoSwitchIfEmpty.java:44)
        reactor.core.publisher.MonoSwitchIfEmpty.subscribe(MonoSwitchIfEmpty.java:44)
        reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:59)
        reactor.core.publisher.Mono.subscribe(Mono.java:3008)
        reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.drain(FluxConcatMap.java:418)
        reactor.core.publisher.FluxConcatMap$ConcatMapImmediate.onSubscribe(FluxConcatMap.java:210)
        reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:128)
        reactor.core.publisher.FluxIterable.subscribe(FluxIterable.java:61)
        reactor.core.publisher.FluxConcatMap.subscribe(FluxConcatMap.java:121)
        reactor.core.publisher.MonoNext.subscribe(MonoNext.java:40)
        reactor.core.publisher.MonoSwitchIfEmpty.subscribe(MonoSwitchIfEmpty.java:44)
        reactor.core.publisher.MonoFlatMap.subscribe(MonoFlatMap.java:60)
        reactor.core.publisher.MonoFlatMap.subscribe(MonoFlatMap.java:60)
        reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
        reactor.core.publisher.MonoPeekTerminal.subscribe(MonoPeekTerminal.java:61)
        reactor.core.publisher.MonoPeekFuseable.subscribe(MonoPeekFuseable.java:74)
        reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
        reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
        reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52)
        reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
        reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
        reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
        reactor.core.publisher.Mono.subscribe(Mono.java:3008)
        reactor.core.publisher.MonoIgnoreThen$ThenIgnoreMain.drain(MonoIgnoreThen.java:167)
        reactor.core.publisher.MonoIgnoreThen.subscribe(MonoIgnoreThen.java:56)
        reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
        reactor.core.publisher.MonoPeekTerminal.subscribe(MonoPeekTerminal.java:61)
        reactor.ipc.netty.channel.ChannelOperations.applyHandler(ChannelOperations.java:383)
        reactor.ipc.netty.http.server.HttpServerOperations.onHandlerStart(HttpServerOperations.java:359)
        io.netty.util.concurrent.AbstractEventExecutor.safeExecute$$$capture(AbstractEventExecutor.java:163)
        io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:403)
        io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:463)
        io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
    Error has been observed by the following operator(s):
        |_  Flux.map(ByteBufFlux.java:68)
        |_  Flux.doOnNext(ByteBufFlux.java:230)
        |_  Flux.map(ReactorServerHttpRequest.java:148)
        |_  Flux.flatMap(AbstractJackson2Decoder.java:95)
        |_  Flux.doFinally(AbstractJackson2Decoder.java:95)
        |_  Flux.map(AbstractJackson2Decoder.java:117)
        |_  Flux.singleOrEmpty(AbstractJackson2Decoder.java:87)
        |_  Operators.error(FluxReceive.java:276)
        |_  Mono.onErrorMap(DefaultServerRequest.java:146)
        |_  Mono.map(ConferenceService.kt:27)
        |_  Mono.map(ConferenceService.kt:32)
        |_  Mono.zipWith(ConferenceService.kt:47)
        |_  Mono.map(ConferenceService.kt:48)
        |_  Flux.flatMap(SimpleReactiveMongoRepository.java:318)
        |_  MonoExtensionsKt.toMono(ConferenceService.kt:55)
        |_  Mono.map(ConferenceService.kt:56)
        |_  Flux.map(AbstractJackson2Encoder.java:99)
        |_  Mono.flatMap(DispatcherHandler.java:177)
        |_  Mono.onErrorResume(DispatcherHandler.java:177)
        |_  Mono.flatMap(DispatcherHandler.java:161)
        |_  Mono.defer(DefaultWebFilterChain.java:71)
        |_  Mono.doOnSuccess(MetricsWebFilter.java:59)
        |_  Mono.doOnError(MetricsWebFilter.java:60)
        |_  Mono.compose(MetricsWebFilter.java:54)
        |_  Mono.defer(DefaultWebFilterChain.java:71)
        |_  Mono.defer(DefaultWebFilterChain.java:71)
3个回答
19

WebClient.exchange()的结果流是单播的

问题实际上在于WebClient每个连接只允许一个订阅者。如果您尝试两次订阅同一交换的连接，则会收到java.lang.IllegalStateException：Only one connection receive subscriber allowed.。

尽管我没有看到您尝试重复使用同一连接的地方，但我相信您可以通过使用下一个操作符组合来解决该问题：

class GeoService() {
   val client = WebClient.create("https://maps.googleapis.com/maps/api/geocode/")

   fun resolveGeoFromCity(city: String): Mono<Geo> {
       return client.get()
            .uri("json?address=$city&key=$API_KEY&language=en")
            .exchange()
            .flatMap { it.bodyToMono(String::class.java) }
            .map { parse(it) }
            .share();
   }
   ...
}

在这个例子中，流被配置为以多播（共享）原始源，只要至少有一个 Subscriber 被订阅。如果你需要所有的订阅者接收相同的数据，你可以将 .share 替换为 .cache 操作符。

此外，还有一种替代上述技术的方法。您可以使用处理器替换提到的操作符，并获得相同的共享可能性：

class GeoService() {

   val client = WebClient.create("https://maps.googleapis.com/maps/api/geocode/")

   fun resolveGeoFromCity(city: String): Mono<Geo> {
       return client.get()
            .uri("json?address=$city&key=$API_KEY&language=en")
            .exchange()
            .flatMap { it.bodyToMono(String::class.java) }
            .map { parse(it) }
            .subscribeWith(DirectProcessor.create());
   }
   ...
}

在这种情况下，你订阅并在调用subscribeWith之后立即运行源数据的消耗，因此在这种情况下，可能会丢失部分数据等。

为什么使用Mono.just(..)一切都正常？

首先，.just是一个冷操作符，它允许尽可能多的订阅者在任何时间点接收相同的数据。这就是为什么当您尝试从连接中两次使用相同的数据块时，没有收到任何异常的原因。

嘿，Oleg。我认为问题在于geo Mono对item Mono的依赖。在订阅时，geo会生成对item的第二个订阅。这是rx-netty所不允许的。 - Nikolay Kuznetsov
我的 Reactor 版本中有 share 运算符。cache 没有帮助。 - Nikolay Kuznetsov
顺便提一下，从您的堆栈中我没有看到任何与“ConferenceService”相关的代码，但错误堆栈直接与代码的这部分相关。 - Oleh Dokuka
我已经将 cache 操作符应用于大多数顶部项目，然后它可以正常工作。 - Nikolay Kuznetsov
嗨@OlehDokuka，我们遇到了相同的问题，但不是与Webclient有关。您能否指导正确的文档以了解、记录和排除此类错误。 - Ivan
显示剩余3条评论
1

我遇到了类似的问题。解决方法是指定此依赖项：

org.springframework:spring-webflux:5.1.4.RELEASE

由于我使用了spring-boot，它部署了之前的版本。不幸的是，这个问题的链接现在不存在。

所以现在我的gradle看起来像这样：

compile('org.springframework.boot:spring-boot-starter-data-mongodb-reactive')
compile('org.springframework.boot:spring-boot-starter-webflux')
// Next 2 dependencies are temporally here until the one above does not resolves next to at least 5.1.4 - where 
// webflux issue is resolved:
// https://github.com/rstoyanchev/spr-issue-migration-test-2/issues/17323
compile('org.springframework:spring-webflux:5.1.4.RELEASE')
compile('org.springframework:spring-web:5.1.4.RELEASE')
截至今天，该原因已不再适用。不出所料，Spring Boot的新版本配备了更新的Spring Webflux版本。例如，Spring Boot 2.7.6配备了Webflux 5.3.24。 - undefined
0

我在这里做了一个非常类似的例子：

这个路由器将从名称获取地理位置，然后使用另一个服务提取日出和日落时间：

我使用了Mono的and方法。

internal fun buildResponse(address: Mono<String>) =
        address.transform(geoLocationService::fromAddress).and(this::sunriseSunset, ::LocationResponse)

internal fun sunriseSunset(geographicCoordinates: GeographicCoordinates) =
        geographicCoordinates.toMono().transform(sunriseSunsetService::fromGeographicCoordinates)

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