code: public Set<String> getCssResources(String containerName) {
  
          CmsFormatterConfig formatterConfig = getFormatterConfig(containerName);
          return formatterConfig != null ? formatterConfig.getCssResources() : Collections.<String> emptySet();
      }
docs: Returns the required css resources.<p>
  
  @param containerName the current container name
  
  @return the required css resources