$result = $gateway->transaction()->sale([
    'amount' => '100.00',
    'paymentMethodNonce' => nonceFromTheClient,
    'purchaseOrderNumber' => '12345',
    'taxAmount' => '5.00',
    'shippingAmount' => '1.00',
    'discountAmount' => '0.00',
    'shipsFromPostalCode' => '60654',
    'shipping' => [
        'firstName' => 'Clinton',
        'lastName' => 'Ecker',
        'streetAddress' => '1234 Main Street',
        'extendedAddress' => 'Unit 222',
        'locality' => 'Chicago',
        'region' => 'IL',
        'postalCode' => '60654',
        'countryCodeAlpha3' => 'USA'
    ],
    'lineItems' => [
        [
            'name' => 'Product',
            'kind' => BraintreeTransactionLineItem::DEBIT,
            'quantity' => '10.0000',
            'unitAmount' => '9.5000',
            'totalAmount' => '95.00',
            'productCode' => '54321',
            'upcCode' => '12345678012',
            // new field
            'upcType' => BraintreeTransactionLineItem::UPC_A,
            // new field
            'imageUrl' => 'https://example.com/product1.jpeg' // new field
        ]
    ]
);

<?php
function sampleIntegration() {
    // Send the package tracking request for the transaction
    $packageResult = Braintree\Transaction::packageTracking(
        $transactionId,
        // Create a Package Tracking request with optional line items
        [
            'carrier' => "UPS",
            'trackingNumber' => "tracking_number_1",
            'notifyPayer' => true,
            'lineItems' => [
                // Optionally create line items
                [
                    'quantity' => '1',
                    'name' => 'Product Name',
                    'productCode' => "ABC 01",
                    'description' => "Product Description",
                    'upcCode' => '12345678012', // new field
                    'upcType' => BraintreeTransactionLineItem::UPC_A, // new field
                    'imageUrl' => 'https://example.com/product1.jpeg' // new field
                ],
                [
                    'quantity' => '1',
                    'name' => 'Product Name',
                    'productCode' => "ABC 02",
                    'description' => "Product Description"
                ]
            ]
        ]
    );
    $id = $packageResult->transaction->packages[0]->id;
    $carrier = $packageResult->transaction->packages[0]->carrier;
    $trackingNumber = $packageResult->transaction->packages[0]->trackingNumber;
    // The PayPal tracker ID will not be immediately available in response to
    // package_tracking(). But should be there when merchant does a findTransaction
    // request at a later stage.
}
?>

<?php
function retrievePackageTracker() {
    // Get more details of the individual packages like so, replace 0 with the element #:
    $transaction = Braintree\Transaction::find($transactionId);
    $id = $transaction->packages[0]->id;
    $carrier = $transaction->packages[0]->carrier;
    $trackingNumber = $transaction->packages[0]->trackingNumber;
    $paypalTrackerId = $transaction->packages[0]->paypalTrackerId;
    // The PayPal tracker ID will not be immediately available in response to
    // package_tracking(). But should be there when merchant does a findTransaction
    // request at a later stage.
}
?>