Sabre SoapClient::__doRequest

sabre-soapclient-dorequest.php

<?php
$sabreSoapServer = ''; // url
$pcc = ''; // sabre pcc
$username = ''; // sabre username
$password = ''; // sabre password

$xmlStr = '<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <soapenv:Header>
      <MessageHeader xmlns="http://www.ebxml.org/namespaces/messageHeader">
         <From>
            <PartyId type="urn:x12.org:IO5:01">CRS</PartyId>
         </From>
         <To>
            <PartyId type="urn:x12.org:IO5:01">Sabre</PartyId>
         </To>
         <CPAId>'.$pcc.'</CPAId>
         <ConversationId>MyConversationID</ConversationId>
         <Service type="string">Cruise</Service>
         <Action>SessionCreateRQ</Action>
         <MessageData>
            <MessageId>1426190858</MessageId>
            <Timestamp>2015-03-12T02:07:38-06:00</Timestamp>
            <TimeToLive>2015-03-12T03:07:38-06:00</TimeToLive>
         </MessageData>
      </MessageHeader>
      <wsse:Security xmlns:wsse="http://schemas.xmlsoap.org/ws/2002/12/secext" xmlns:wsu="http://schemas.xmlsoap.org/ws/2002/12/utility">
         <wsse:UsernameToken>
            <wsse:Username>'.$username.'</wsse:Username>
            <wsse:Password>'.$password.'</wsse:Password>
            <Organization>'.$pcc.'</Organization>
            <Domain>DEFAULT</Domain>
         </wsse:UsernameToken>
      </wsse:Security>
   </soapenv:Header>
   <soapenv:Body>
      <SessionCreateRQ xmlns="http://www.opentravel.org/OTA/2002/11">
         <POS>
            <Source PseudoCityCode="'.$pcc.'" />
         </POS>
      </SessionCreateRQ>
   </soapenv:Body>
</soapenv:Envelope>';

$client = new SoapClient(null, array(
	'location' => $sabreSoapServer,
	'uri' => $sabreSoapServer,
	'trace' => 1,
	'exceptions' => true, 
	'use' => 'wse'
));

$response = $client->__doRequest($xmlStr, $sabreSoapServer, $sabreSoapServer, '1');

how to get this response in array?