### Question:
ApplicationBuilder extends AbstractBuilder<ApplicationConfig, ApplicationBuilder> { public ApplicationBuilder logger(String logger) { this.logger = logger; return getThis(); }  static ApplicationBuilder newBuilder(); ApplicationBuilder name(String name); ApplicationBuilder metadata(String metadata); ApplicationBuilder version(String version); ApplicationBuilder owner(String owner); ApplicationBuilder organization(String organization); ApplicationBuilder architecture(String architecture); ApplicationBuilder environment(String environment); ApplicationBuilder compiler(String compiler); ApplicationBuilder logger(String logger); ApplicationBuilder addRegistry(RegistryConfig registry); ApplicationBuilder addRegistries(List<? extends RegistryConfig> registries); ApplicationBuilder registryIds(String registryIds); ApplicationBuilder monitor(MonitorConfig monitor); ApplicationBuilder monitor(String monitor); ApplicationBuilder isDefault(Boolean isDefault); ApplicationBuilder dumpDirectory(String dumpDirectory); ApplicationBuilder qosEnable(Boolean qosEnable); ApplicationBuilder qosPort(Integer qosPort); ApplicationBuilder qosAcceptForeignIp(Boolean qosAcceptForeignIp); ApplicationBuilder shutwait(String shutwait); ApplicationBuilder appendParameter(String key, String value); ApplicationBuilder appendParameters(Map<String, String> appendParameters); ApplicationBuilder metadataServicePort(Integer metadataServicePort); ApplicationConfig build();  }### Answer:
@Test void logger() { ApplicationBuilder builder = new ApplicationBuilder(); builder.logger("log4j"); Assertions.assertEquals("log4j", builder.build().getLogger()); }