QName sequenceQName = wsrmConstants.getSequenceQName();
SOAPElement sequenceElement = soapEnvelope.getHeader().addChildElement(sequenceQName);
// write required wsrm:Identifier element
QName identifierQName = wsrmConstants.getIdentifierQName();
sequenceElement.addChildElement(identifierQName).setValue(o.getIdentifier());
// write required wsrm:MessageNumber element
QName messageNumberQName = wsrmConstants.getMessageNumberQName();
SOAPElement messageNumberElement = sequenceElement.addChildElement(messageNumberQName);
messageNumberElement.setValue(String.valueOf(o.getMessageNumber()));