@Test
public void validTopic(TestContext context) {

    TopicRequest request = new TopicRequest(PREFIX + "my.topic.x");
    final Optional<String> optTopic = extractor.extractTopic(request);
    context.assertTrue(optTopic.isPresent());
    context.assertEquals("my.topic.x", optTopic.get());
    TopicRequest request2 = new TopicRequest(PREFIX + "abc/def/ghi/123");
    final Optional<String> optTopic2 = extractor.extractTopic(request2);
    context.assertTrue(optTopic2.isPresent());
    context.assertEquals("abc/def/ghi/123", optTopic2.get());
}