How to retrieve WebSession using WebFlux and WebSocketSession in latest versions of spring?

I have been trying to retrieve the WebSession from WebSocketSessionHandler (namespace: org.springframework.web.reactive.socket) in order to use it in my send consumer (using FluxSink).

I have been digging through the whole spring source code and documentations which didn't seem up to date yet and I didn't find anything about the last versions.

Is it possible to retrieve the WebSession or are there ways to get only the id?

Here is sample code: WebSocketHandler.java

public class WebSocketHandler implements org.springframework.web.reactive.socket.WebSocketHandler {
    /**
     * {@inheritDoc}
     */
    @Override
    public Mono<Void> handle(final WebSocketSession session) {
        // use session to receive message etc...
        return (session.send(Flux.create((FluxSink<OutputMessageInterface> sink) -> {
            // use sink
        }).map(/* ... convert from string to WebSocketMessage ... */)));
    }
}

And the configuration file: WebSocketConfiguration.java

@Configuration
public class WebSocketConfiguration {
    @Bean
    public WebSocketHandler webSocketHandler() {
        return (new WebSocketHandler());
    }

    @Bean
    public WebSocketHandlerAdapter handlerAdapter() {
        return (new WebSocketHandlerAdapter());
    }

    @Bean
    public HandlerMapping handlerMapping(@Autowired WebSocketHandler webSocketHandler) {
        Map<String, WebSocketHandler> map = new HashMap<>();
        SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();

        map.put("/realtime", webSocketHandler);
        mapping.setOrder(10);
        mapping.setUrlMap(map);
        return (mapping);
    }
}

The project is based on spring-boot 2.0.0.M6, spring-boot-starter-webflux 2.0.0.M6 (spring-core 5.0.1.RELEASE)