Is there an analogue of RxJava Subject in Reactor?

Question

Java

Hello.
Understanding the reactor&

In RxJava there is such a thing - Subject - it is both an Observable and an Observer - that is, it can emit messages as an Observer, and at the same time you can subscribe to it (because Observable)

Is there something similar in the reactor? As I understand it, in his terms - he must implement both FluxSink and Flux itself at the same time.

Thanks in advance.