Support additional SOAP headers

Hi. How can I set this code?

```
$client = new SoapClient($wsdlPath, $options);
$client->__setSoapHeaders(
            new SoapHeader(
                'http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd',
                'Security',
                new SoapVar($xml, XSD_ANYXML),
                true
            )
        );
```