RobRichards\WsePhp\WSSESoap::AddReference PHP Method

    public function AddReference($baseNode, $guid)
    {
        $refList = null;
        $child = $baseNode->firstChild;
        while ($child) {
            if ($child->namespaceURI == XMLSecEnc::XMLENCNS && $child->localName == 'ReferenceList') {
                $refList = $child;
                break;
            }
            $child = $child->nextSibling;
        }
        $doc = $baseNode->ownerDocument;
        if (is_null($refList)) {
            $refList = $doc->createElementNS(XMLSecEnc::XMLENCNS, 'xenc:ReferenceList');
            $baseNode->appendChild($refList);
        }
        $dataref = $doc->createElementNS(XMLSecEnc::XMLENCNS, 'xenc:DataReference');
        $refList->appendChild($dataref);
        $dataref->setAttribute('URI', '#' . $guid);
    }