metadata example

class MessageMediaOptionsTest extends TestCase
{
    public function testMessageMediaOptions()
    {
        $messageMediaOptions = (new MessageMediaOptions())->
            media(['test_media'])
            ->callbackUrl('test_callback_url')
            ->format('test_format')
            ->deliveryReport(true)
            ->expiry(999)
            ->metadata(['test_metadata'])
            ->scheduled('test_scheduled')
            ->subject('test_subject');

        self::assertSame([
            'media' => ['test_media'],
            'callback_url' => 'test_callback_url',
            'format' => 'test_format',
            'delivery_report' => true,
            'message_expiry_timestamp' => 999,
            'metadata' => ['test_metadata'],
            'scheduled' => 'test_scheduled',