code: public static final SupportedCSS getSupportedCSS() {
  		if (css == null) {
  			try {
  				@SuppressWarnings("unchecked")
  				Class<? extends SupportedCSS> clazz = (Class<? extends SupportedCSS>) Class
  						.forName(DEFAULT_SUPPORTED_CSS);
  				Method m = clazz.getMethod("getInstance");
  				registerSupportedCSS((SupportedCSS) m.invoke(null));
  				log.debug(
  						"Retrived {} as default SupportedCSS implementation.",
  						DEFAULT_SUPPORTED_CSS);
  			} catch (Exception e) {
  				log.error("Unable to get SupportedCSS from default", e);
  				throw new RuntimeException(
  						"No SupportedCSS implementation registered!");
  			}
  		}
  		return css;
  	}
docs: Returns registered SupportedCSS
  
  @return SupportedCSS instance