基于PHP的SOAP头如何生成特定格式?

I wanted to generate the following SOAP header format,

<soapenv:Header>
    <SoapHeaderMsg xmlns="http://xyz.com.au">
        <opt:UserSoapHeader>
            <opt:IdentityName>TEST</opt:IdentityName>
            <opt:AuthenticationToken>jjjkjkjkjkjkj</opt:AuthenticationToken>
        </opt:UserSoapHeader>
    </SoapHeaderMsg>
</soapenv:Header>

So i am using the following php functions to generate this,

$this->__setSoapHeaders(array(
            new SoapHeader('http://xyz.com.au', 'SoapHeaderMsg', array(
                new SoapHeader('http://xyz.com.au', 'IdentityName', 'TEST'),
                new SoapHeader('http://xyz.com.au', 'AuthenticationToken', 'jkjkjkk')
            )),
        ));

Which generates following headers which is completely different to what i wanted above ? how do i generate exact same headers using PHP functions like above ?

<SOAP-ENV:Header>
        <ns1:SoapHeaderMsg>
            <SOAP-ENC:Struct>
                <namespace>http://xyz.com.au</namespace>
                <name>IdentityName</name>
                <data>TEST</data>
                <mustUnderstand>false</mustUnderstand>
            </SOAP-ENC:Struct>
            <SOAP-ENC:Struct>
                <namespace>http://xyz.com.au</namespace>
                <name>AuthenticationToken</name>
                <data>hjhhjjhjhjhj</data>
                <mustUnderstand>false</mustUnderstand>
            </SOAP-ENC:Struct>
        </ns1:SoapHeaderMsg>
    </SOAP-ENV:Header>

array is mostly used on the PHP side, which gets converted to Struct. Can you please try to use object and see if you have any success with it.

$this->__setSoapHeaders(array(
        new SoapHeader('http://xyz.com.au', 'SoapHeaderMsg', 
            (object)array( 
                'opt:UserSoapHeader' => (object)array(
                    'opt:IdentityName' => 'TEST',
                    'opt:AuthenticationToken' => 'jkjkjkk'
                )
        )),
    ));

The request looks like below:

<?xml version="1.0" encoding="utf-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
                   xmlns:ns1="http://test.domain.com/"
                   xmlns:ns2="http://xyz.com.au">
      <SOAP-ENV:Header>
        <ns2:SoapHeaderMsg>
              <opt:UserSoapHeader>
                    <opt:IdentityName>TEST</opt:IdentityName>
                    <opt:AuthenticationToken>jkjkjkk</opt:AuthenticationToken>
              </opt:UserSoapHeader>
        </ns2:SoapHeaderMsg>
      </SOAP-ENV:Header>
      <SOAP-ENV:Body>
            ......
      </SOAP-ENV:Body>
</SOAP-ENV:Envelope>