Why is @Bean SamplerFunction<MessagingRequest> trySample never executed?

In project with spring-cloud-stream, rabbitmq and spring-cloud-sleuth my SamplerFunction<MessagingRequest>.trySample is never executed. Where can be a problem? Bean is in a correct @Configuration class (other beans are created and work).

`spring.sleuth.sampler.probability: 0.001

@Bean
SamplerFunction<MessagingRequest> zipkinSampler() {
    return new Zipkin.ZipkinSampler();
}

public static class ZipkinSampler implements SamplerFunction<MessagingRequest> {

    private SamplerFunction<MessagingRequest> sampler = MessagingRuleSampler.newBuilder()
            .putRule(channelNameEquals("alertsNever"), Sampler.NEVER_SAMPLE)
            .putRule(channelNameEquals("rabbitChannel"), RateLimitingSampler.create(1))
            .putRule(Matchers.alwaysMatch(), RateLimitingSampler.create(100))
            .build();;

    @Override
    public Boolean trySample(final MessagingRequest request) {
        log.info("trySample {}, channelKind: {}, channelName: {}, operation: {}", request, request.channelKind(), request.channelName(), request.operation());

        return sampler.trySample(request);
    }
}`

[gindex]

Here is a sample repository to reproduce the issue https://github.com/gindex/sleuth-rabbit-issue

[spring-cloud-issues]

Closing due to lack of requested feedback. If you would like us to look at this issue, please provide the requested information and we will re-open the issue.