code: @SuppressWarnings("rawtypes")
      protected PropertiesHolder getProperties(final String filename, final Resource resource) {
  	    return CacheEntry.getValue(cachedProperties, filename, fileCacheMillis, new Callable<PropertiesHolder>() {
              @Override
              public PropertiesHolder call() throws Exception {
                  return new PropertiesHolder(filename, resource);
              }
          }, new Callable<CacheEntry>() {
              @Override
              public CacheEntry call() throws Exception {
                  return new PropertiesHolderCacheEntry();
              }
          }, true, null);
  	}
docs: Get a PropertiesHolder for the given filename, either from the
  cache or freshly loaded.
  @param filename the bundle filename (basename + Locale)
  @return the current PropertiesHolder for the bundle