public static String prepNAStrings(String na){
  return na + DataExpression.DELIM_NA_STRING_SEP + "dummy";
}

public static String prepNAStrings ( String na ) { return na + DataExpression . DELIM_NA_STRING_SEP + "dummy" ; }
prepare na strings so that they can be sent to workers via jobconf . a " dummy " string is added at the end to handle the case of empty strings .
