### Question:
RecommendationVerticle extends AbstractVerticle { static String parseContainerIdFromHostname(String hostname) { return hostname.replaceAll("recommendation-v\\d+-", ""); }  @Override void start(); static void main(String[] args);  }### Answer:
@Test public void parseContainerIdFromHostname() { assertThat(RecommendationVerticle.parseContainerIdFromHostname("recommendation-v1-abcdef"), equalTo("abcdef")); assertThat(RecommendationVerticle.parseContainerIdFromHostname("recommendation-v2-abcdef"), equalTo("abcdef")); assertThat(RecommendationVerticle.parseContainerIdFromHostname("recommendation-v10-abcdef"), equalTo("abcdef")); assertThat(RecommendationVerticle.parseContainerIdFromHostname("unknown"), equalTo("unknown")); assertThat(RecommendationVerticle.parseContainerIdFromHostname("localhost"), equalTo("localhost")); }