@Test
  public void testResolve_OsSpecifics() throws Exception {
    Map<String, ServiceOsSpecific> osSpecifics = new HashMap<String, ServiceOsSpecific>();
    osSpecifics.put("foo", new ServiceOsSpecific());

    // specified in child only
    ServiceInfo info = new ServiceInfo();
    ServiceInfo parentInfo = new ServiceInfo();
    info.setOsSpecifics(osSpecifics);

    ServiceModule service = resolveService(info, parentInfo);
    assertEquals(osSpecifics, service.getModuleInfo().getOsSpecifics());

    // specified in parent only
    info.setOsSpecifics(null);
    parentInfo.setOsSpecifics(osSpecifics);

    service = resolveService(info, parentInfo);
    assertEquals(osSpecifics, service.getModuleInfo().getOsSpecifics());

    // specified in both
    Map<String, ServiceOsSpecific> osSpecifics2 = new HashMap<String, ServiceOsSpecific>();
    osSpecifics.put("bar", new ServiceOsSpecific());

    info.setOsSpecifics(osSpecifics);
    parentInfo.setOsSpecifics(osSpecifics2);

    service = resolveService(info, parentInfo);
    assertEquals(osSpecifics, service.getModuleInfo().getOsSpecifics());
  }
  @Override
  public void resolve(
      ServiceModule parentModule,
      Map<String, StackModule> allStacks,
      Map<String, ServiceModule> commonServices)
      throws AmbariException {

    if (!serviceInfo.isValid() || !parentModule.isValid()) return;

    ServiceInfo parent = parentModule.getModuleInfo();

    if (serviceInfo.getComment() == null) {
      serviceInfo.setComment(parent.getComment());
    }
    if (serviceInfo.getDisplayName() == null) {
      serviceInfo.setDisplayName(parent.getDisplayName());
    }
    if (serviceInfo.getVersion() == null) {
      serviceInfo.setVersion(parent.getVersion());
    }

    if (serviceInfo.getRequiredServices() == null
        || serviceInfo.getRequiredServices().size() == 0) {
      serviceInfo.setRequiredServices(
          parent.getRequiredServices() != null
              ? parent.getRequiredServices()
              : Collections.<String>emptyList());
    }

    if (serviceInfo.isRestartRequiredAfterChange() == null) {
      serviceInfo.setRestartRequiredAfterChange(parent.isRestartRequiredAfterChange());
    }
    if (serviceInfo.isRestartRequiredAfterRackChange() == null) {
      serviceInfo.setRestartRequiredAfterRackChange(parent.isRestartRequiredAfterRackChange());
    }
    if (serviceInfo.isMonitoringService() == null) {
      serviceInfo.setMonitoringService(parent.isMonitoringService());
    }
    if (serviceInfo.getOsSpecifics().isEmpty()) {
      serviceInfo.setOsSpecifics(parent.getOsSpecifics());
    }
    if (serviceInfo.getCommandScript() == null) {
      serviceInfo.setCommandScript(parent.getCommandScript());
    }
    if (serviceInfo.getServicePackageFolder() == null) {
      serviceInfo.setServicePackageFolder(parent.getServicePackageFolder());
    }
    if (serviceInfo.getMetricsFile() == null) {
      serviceInfo.setMetricsFile(parent.getMetricsFile());
    }
    if (serviceInfo.getAlertsFile() == null) {
      serviceInfo.setAlertsFile(parent.getAlertsFile());
    }
    if (serviceInfo.getKerberosDescriptorFile() == null) {
      serviceInfo.setKerberosDescriptorFile(parent.getKerberosDescriptorFile());
    }
    if (serviceInfo.getThemesMap().isEmpty()) {
      serviceInfo.setThemesMap(parent.getThemesMap());
    }
    if (serviceInfo.getWidgetsDescriptorFile() == null) {
      serviceInfo.setWidgetsDescriptorFile(parent.getWidgetsDescriptorFile());
    }

    mergeCustomCommands(parent.getCustomCommands(), serviceInfo.getCustomCommands());
    mergeConfigDependencies(parent);
    mergeComponents(parentModule, allStacks, commonServices);
    mergeConfigurations(parentModule, allStacks, commonServices);
    mergeThemes(parentModule, allStacks, commonServices);
    mergeExcludedConfigTypes(parent);

    mergeServiceProperties(parent.getServicePropertyList());
  }