public function getXML($request)
{
$doc = new \DOMDocument('1.0');
$doc->loadXML($request);
$objWSSE = new WSSESoap($doc);
$objWSSE->addTimestamp();
$objKey = new XMLSecurityKey(XMLSecurityKey::RSA_SHA256, ['type' => 'private']);
$objKey->loadKey($this->key, TRUE);
$objWSSE->signSoapDoc($objKey, ["algorithm" => XMLSecurityDSig::SHA256]);
$token = $objWSSE->addBinaryToken(file_get_contents($this->cert));
$objWSSE->attachTokentoSig($token);
return $objWSSE->saveXML();
}