如何从2个给定的Flux中获取一个公共元素？

import reactor.core.publisher.Flux;
import java.util.HashSet;
import java.util.Set;

Flux<Integer> flux1 = Flux.just(1, 2, 3, 4, 5);
Flux<Integer> flux2 = Flux.just(4, 5, 6, 7, 8);

Set<Integer> set1 = flux1.collect(Collectors.toSet()).block();
Set<Integer> set2 = flux2.collect(Collectors.toSet()).block();

Set<Integer> commonElements = new HashSet<>();

for (Integer element : set1) {
    if (set2.contains(element)) {
        commonElements.add(element);
    }
}

System.out.println("公共元素：" + commonElements);