code: public static int cleanImageCache(float maxAge) {
  
          // calculate oldest possible date for the cache files
          long expireDate = System.currentTimeMillis() - (long)(maxAge * 60f * 60f * 1000f);
          File basedir = new File(CmsImageLoader.getImageRepositoryPath());
          // perform the cache cleanup
          return cleanImageCache(expireDate, basedir);
      }
docs: Removes all expired image cache entries from the RFS cache.<p>
  
  Empty directories are removed as well.<p>
  
  @param maxAge the maximum age of the image cache files in hours (or fractions of hours)
  
  @return the total number of deleted resources