public static VALUE_TYPE getEnum(String value){
            VALUE_TYPE retVal = null;
            if(value != null){
                if(value.equals("DATE")){
                    return DATE;
                } else if(value.equals("DATE-TIME")){
                    return DATE_TIME;
                } else if(value.equals("PERIOD")){
                    return PERIOD;
                }
            } else {
                throw new IllegalArgumentException();
            }
            return retVal;
        }