### Question:
ApplicationBuilder extends AbstractBuilder<ApplicationConfig, ApplicationBuilder> { public ApplicationBuilder appendParameter(String key, String value) { this.parameters = appendParameter(parameters, key, value); 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 appendParameter() { ApplicationBuilder builder = new ApplicationBuilder(); builder.appendParameter("default.num", "one").appendParameter("num", "ONE"); Map<String, String> parameters = builder.build().getParameters(); Assertions.assertTrue(parameters.containsKey("default.num")); Assertions.assertEquals("ONE", parameters.get("num")); }