PayPal\Api\VerifyWebhookSignature::setTransmissionId PHP Method

    public function setTransmissionId($transmission_id)
    {
        $this->transmission_id = $transmission_id;
        return $this;
    }

// $bodyReceived = file_get_contents('php://input');
$headers = array('Client-Pid' => '14910', 'Cal-Poolstack' => 'amqunphttpdeliveryd:UNPHTTPDELIVERY*CalThreadId=0*TopLevelTxnStartTime=1579e71daf8*Host=slcsbamqunphttpdeliveryd3001', 'Correlation-Id' => '958be65120106', 'Host' => 'shiparound-dev.de', 'User-Agent' => 'PayPal/AUHD-208.0-25552773', 'Paypal-Auth-Algo' => 'SHA256withRSA', 'Paypal-Cert-Url' => 'https://api.sandbox.paypal.com/v1/notifications/certs/CERT-360caa42-fca2a594-a5cafa77', 'Paypal-Auth-Version' => 'v2', 'Paypal-Transmission-Sig' => 'eDOnWUj9FXOnr2naQnrdL7bhgejVSTwRbwbJ0kuk5wAtm2ZYkr7w5BSUDO7e5ZOsqLwN3sPn3RV85Jd9pjHuTlpuXDLYk+l5qiViPbaaC0tLV+8C/zbDjg2WCfvtf2NmFT8CHgPPQAByUqiiTY+RJZPPQC5np7j7WuxcegsJLeWStRAofsDLiSKrzYV3CKZYtNoNnRvYmSFMkYp/5vk4xGcQLeYNV1CC2PyqraZj8HGG6Y+KV4trhreV9VZDn+rPtLDZTbzUohie1LpEy31k2dg+1szpWaGYOz+MRb40U04oD7fD69vghCrDTYs5AsuFM2+WZtsMDmYGI0pxLjn2yw==', 'Paypal-Transmission-Time' => '2016-09-21T22:00:46Z', 'Paypal-Transmission-Id' => 'd938e770-8046-11e6-8103-6b62a8a99ac4', 'Accept' => '*/*');
/**
* Receive HTTP headers that you received from PayPal webhook.
* Just uncomment the below line to read the data from actual request.
*/
/** @var Array $headers */
//$headers = getallheaders();
/**
* In Documentions https://developer.paypal.com/docs/api/webhooks/#verify-webhook-signature_post 
* All header keys as UPPERCASE, but I recive the header key as the example array, First letter as UPPERCASE
*/
$headers = array_change_key_case($headers, CASE_UPPER);
$signatureVerification = new VerifyWebhookSignature();
$signatureVerification->setAuthAlgo($headers['PAYPAL-AUTH-ALGO']);
$signatureVerification->setTransmissionId($headers['PAYPAL-TRANSMISSION-ID']);
$signatureVerification->setCertUrl($headers['PAYPAL-CERT-URL']);
$signatureVerification->setWebhookId("9XL90610J3647323C");
// Note that the Webhook ID must be a currently valid Webhook that you created with your client ID/secret.
$signatureVerification->setTransmissionSig($headers['PAYPAL-TRANSMISSION-SIG']);
$signatureVerification->setTransmissionTime($headers['PAYPAL-TRANSMISSION-TIME']);
$webhookEvent = new WebhookEvent();
$webhookEvent->fromJson($requestBody);
$signatureVerification->setWebhookEvent($webhookEvent);
$request = clone $signatureVerification;
try {
    /** @var \PayPal\Api\VerifyWebhookSignatureResponse $output */
    $output = $signatureVerification->post($apiContext);
} catch (Exception $ex) {
    // NOTE: PLEASE DO NOT USE RESULTPRINTER CLASS IN YOUR ORIGINAL CODE. FOR SAMPLE ONLY
    ResultPrinter::printError("Validate Received Webhook Event", "WebhookEvent", null, $request->toJSON(), $ex);