@Override
 public String toString(String[] value) {
   String result = ArrayTools.toString(value, 0, value.length, ",");
   if (StrTools.countIndexOf(result, ',') != value.length - 1) {
     log.fatal("StringArrayField cannot contain , in '%s'", result);
   }
   return result;
 }
 @Override
 public String toString(double[] value) {
   return ArrayTools.toString(value, 0, value.length, ",");
 }