private ZoneId parseExpiryZone(XmlElement expirationTimeEl, FpmlDocument document)
{
string businessCenter = expirationTimeEl.getChild("businessCenter").Content;
Optional <ZoneId> optionalZoneId = document.getZoneId(businessCenter);
if (!optionalZoneId.Present)
{
throw new FpmlParseException("Unknown businessCenter" + " attribute value: " + businessCenter);
}
return(optionalZoneId.get());
}