class ResourceImpl implements Resource {

  @Override
  public void addCategory(String id) {
    String categoryKey = getCategoryKey(id);

    if (!propertiesMap.containsKey(categoryKey)) {
      propertiesMap.put(categoryKey, new HashMap<>());
    }
  }

  public  ResourceImpl(Type type);
  public  ResourceImpl(Resource resource);
  public  ResourceImpl(Resource resource, Set<String> propertyIds);

}