Use of toolkit through ESB : invalid soap-header

[StefaanSomers]

We do our communication with Salesfore not directly, but through Enterprise Solution Bus. So we don't need to login anymore to salesforce, but just the API-request to the ESB who will do his communication with Salesforce. But the ESB needs a special soap-header.

<soapenv:Header>
    <ns1:header soapenv:actor=“http://schemas.xmlsoap.org/soap/actor/next” soapenv:mustUnderstand=“0” xmlns:ns1=“http://www.xxxx.com/xsd/esb/ESBCommonTypes”>
    <ns1:message_type>SF_ENTPRISE_Interface</ns1:message_type>
    <ns1:version>01.80</ns1:version>
    <ns1:source_entity>xxxx</ns1:source_entity>
    <ns1:source_application>xxx</ns1:source_application>
    <ns1:destination_entity>xxx</ns1:destination_entity>
    <ns1:destination_application>xxx</ns1:destination_application>
    <ns1:message_id></ns1:message_id></ns1:header>
</soapenv:Header>

So I try to modify SfBaseClient, the method

private function setHeaders($call=NULL) {
......

      $soapHeader=new SoapHeader('http://www.leaseplan.com/xsd/esb/ESBCommonTypes', 'header', array (
            'client'=> 'test',
            'defaultNamespace'=> 'test',
            'message_type' => 'xxxx',
            'version' => '01.80',
            'source_entity' => 'xxx',
            'source_application' => 'LNOTES',
            'destination_entity'=> 'xx',
            'destination_application'=> 'SFxxxBE'
        ));


        array_push($header_array, $soapHeader);

        $this->sforce->__setSoapHeaders($header_array);

But when doing this, I always get
Fatal error: SoapClient::__setSoapHeaders(): Invalid SOAP header in C:\var\sourceRepositories\salesforce\Force.com-Toolkit-for-PHP-master\soapclient\SforceBaseClient.php on line 337

How can I obtain this functionality