如何在PHP中从以下SOAP XML响应中获取pinBlocked标记

<?php
// 发送SOAP请求并获取响应
$client = new SoapClient("http://example.com/soap/wsdl");
$response = $client->someSoapMethod();

// 解析SOAP XML响应
$xml = new SimpleXMLElement($response);

// 使用XPath表达式找到包含pinBlocked标记的节点
$pinBlockedNode = $xml->xpath("//pinBlocked");

// 提取pinBlocked标记的值
if ($pinBlockedNode) {
    $pinBlocked = (string) $pinBlockedNode[0];
    // 进行相应处理
    if ($pinBlocked === 'true') {
        echo "pinBlocked标记为真";
    } else {
        echo "pinBlocked标记为假";
    }
} else {
    echo "未找到pinBlocked标记";
}
?>

<SOAP-ENV:Envelope>
    <SOAP-ENV:Body>
        <response>
            <pinBlocked>true</pinBlocked>
        </response>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>