private Date processStartDate(boolean required) throws ParseException {
        Date startDate = null;
        if (commandLine.hasOption(OPTION_START_DATE)) {
            startDate = parseDateTime(commandLine.getOptionValue(OPTION_START_DATE));
        }
        if (required && startDate == null) {
            throwMissingOptionException("The startDate is required for this option.");
        }
        return startDate;
    }