private Period parsePeriod(XMLDocument xmlDoc, String checkDataQueryPath) throws XPathExpressionException { final String periodValue = parseTextValue(xmlDoc, checkDataQueryPath + CHKDATA_DOMAIN_PERIOD_EXPR); final String unitValue = parseTextValue(xmlDoc, checkDataQueryPath + CHKDATA_DOMAIN_PERIOD_UNIT_EXPR); return (periodValue != null) ? new Period(PeriodUnit.value(unitValue), Integer.parseInt(periodValue)) : null; }