private void mergeExcludedConfigTypes(ServiceInfo parent){
    if (serviceInfo.getExcludedConfigTypes() == null){
      serviceInfo.setExcludedConfigTypes(parent.getExcludedConfigTypes());
    } else if (parent.getExcludedConfigTypes() != null){
      Set<String> resultExcludedConfigTypes = serviceInfo.getExcludedConfigTypes();
      for (String excludedType : parent.getExcludedConfigTypes()) {
        if (!resultExcludedConfigTypes.contains(excludedType)){
          resultExcludedConfigTypes.add(excludedType);
        }
      }
      serviceInfo.setExcludedConfigTypes(resultExcludedConfigTypes);
    }

  }
Merge excluded configs types with parent.  Child values override parent values.

@param parent parent service module
ambari-server/src/main/java/org/apache/ambari/server/stack/ServiceModule.java