private static long logStoreFiles(StringLogger.LineLogger logger, String prefix, File dir) {
   if (!dir.isDirectory()) return 0;
   File[] files = dir.listFiles();
   if (files == null) {
     logger.logLine(prefix + "<INACCESSIBLE>");
     return 0;
   }
   long total = 0;
   for (File file : files) {
     long size;
     String filename = file.getName();
     if (file.isDirectory()) {
       logger.logLine(prefix + filename + ":");
       size = logStoreFiles(logger, prefix + "  ", file);
       filename = "- Total";
     } else {
       size = file.length();
     }
     logger.logLine(prefix + filename + ": " + Format.bytes(size));
     total += size;
   }
   return total;
 }
 private String time() {
   return Format.date();
 }