Flux.sample() behaviour in reactor-core 3.0.2.RELEASE

Sample.java

package io.pivotal.literx;

import org.junit.Test;
import reactor.core.publisher.Flux;

public class Sample {
    @Test
    public void sample() {
        Flux<Integer> flux = Flux.just(1, 2, 3);
        flux.log().sampleMillis(1000).subscribe(a -> System.out.println("Subscribe: " + a));
        System.out.println("Done");
    }
}

stdout.txt

21:21:27.012 [main] DEBUG reactor.util.Loggers$LoggerFactory - Using Slf4j logging framework
21:21:27.073 [main] INFO  reactor.Flux.Array.1 - | onSubscribe(reactor.core.publisher.FluxArray$ArraySubscription@2b9627bc)
21:21:27.076 [main] INFO  reactor.Flux.Array.1 - | request(unbounded)
21:21:27.076 [main] INFO  reactor.Flux.Array.1 - | onNext(1)
21:21:27.076 [main] INFO  reactor.Flux.Array.1 - | onNext(2)
21:21:27.076 [main] INFO  reactor.Flux.Array.1 - | onNext(3)
21:21:27.077 [main] INFO  reactor.Flux.Array.1 - | onComplete()
Done

Process finished with exit code 0