Wyświetlanie zapytania i odpowiedzi w xml z SoapClienta

$C = new SoapClient('webservice.wsdl', array( 'trace' => 1 ) );
print "REQUEST:".$C->__getLastRequest()."";
print "RESPONSE:" .$C->__getLastResponse()."";

lub

print "REQUEST:".htmlspecialchars($C->__getLastRequest())."";
print "RESPONSE:" .htmlspecialchars($C->__getLastResponse())."";