Description:
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I need to add an http header to a Soap request using SoapClient class.
The way I found in documentation is using 'stream_context' of '$options' constructor's parameter. But the class doesn't consider that option, either in "wsdl" mode and "non wsdl" mode. So the target web service doesn't receive the added  http header.

Reproduce code:
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$additionalHeader = array( 'http'=>array('header' => "Token: 123"));
$context = stream_context_create($additionalHeader);
$clientSoap = new SOAPClient('http://yoururl/yourwsdl.wsdl',
array('trace' => 1, 'stream_context' => $context, 'exceptions' => false));
$clientSoap->yourMethod($yourParameter);

Expected result:
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Target web service receives an http header named 'Token' with value "123"

Actual result:
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Target web service doesn't receive an http header named 'Token' with value "123"