Braintree\WebhookNotification::parse PHP Method

    public static function parse($signature, $payload)
    {
        if (preg_match("/[^A-Za-z0-9+=\\/\n]/", $payload) === 1) {
            throw new Exception\InvalidSignature("payload contains illegal characters");
        }
        Configuration::assertGlobalHasAccessTokenOrKeys();
        self::_validateSignature($signature, $payload);
        $xml = base64_decode($payload);
        $attributes = Xml::buildArrayFromXml($xml);
        return self::factory($attributes['notification']);
    }

 public function testBuildsASampleNotificationForAPartnerMerchantDeclinedWebhook()
 {
     $sampleNotification = Braintree\WebhookTesting::sampleNotification(Braintree\WebhookNotification::PARTNER_MERCHANT_DECLINED, "my_id");
     $webhookNotification = Braintree\WebhookNotification::parse($sampleNotification['bt_signature'], $sampleNotification['bt_payload']);
     $this->assertEquals(Braintree\WebhookNotification::PARTNER_MERCHANT_DECLINED, $webhookNotification->kind);
     $this->assertEquals("abc123", $webhookNotification->partnerMerchant->partnerMerchantId);
 }