code: final Cache loadExternalCache(String classSimpleName) {
  		ServiceLoader<Cache> cacheLoader = ServiceLoader.load(Cache.class, Para.getParaClassLoader());
  		for (Cache cache : cacheLoader) {
  			if (cache != null && classSimpleName.equalsIgnoreCase(cache.getClass().getSimpleName())) {
  				return cache;
  			}
  		}
  		return null;
  	}
docs: Scans the classpath for Cache implementations, through the
  {@link ServiceLoader} mechanism and returns one.
  @param classSimpleName the name of the class name to look for and load
  @return a Cache instance if found, or null