class ExampleMeatballSandwich

class ExampleMeatballSandwich extends SandwichBase implements ContainerFactoryPluginInterface {
    // Use Drupal\Core\StringTranslation\StringTranslationTrait to define
    // $this->t() for string translations in our plugin.
    use StringTranslationTrait;
    
    /**
     * The day the sandwich is ordered.
     *
     * Since meatball sandwiches have a special behavior on Sundays, and since we
     * want to test that behavior on days other than Sunday, we have to store the
     * day as a property so we can test it.
     *
     * This is the string representation of the day of the week you get from
     * date('D').
     *
     * @var string
     */
    protected $day;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        // This class needs to translate strings, so we need to inject the string
        // translation service from the container. This means our plugin class has
        // to implement ContainerFactoryPluginInterface. This requires that we make
        // this create() method, and use it to inject services from the container.
        // @see https://www.drupal.org/node/2012118
        $sandwich = new static($configuration, $plugin_id, $plugin_definition, $container->get('string_translation'));
        return $sandwich;
    }
    
    /**
     * {@inheritdoc}
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, TranslationInterface $translation) {
        // Store the translation service.
        $this->setStringTranslation($translation);
        // Store the day so we can generate a special description on Sundays.
        $this->day = date('D');
        // Pass the other parameters up to the parent constructor.
        parent::__construct($configuration, $plugin_id, $plugin_definition);
    }
    
    /**
     * {@inheritdoc}
     */
    public function order(array $extras) {
        $ingredients = [
            'meatballs',
            'irresistible marinara sauce',
        ];
        $sandwich = array_merge($ingredients, $extras);
        return 'You ordered an ' . implode(', ', $sandwich) . ' sandwich. Enjoy!';
    }
    
    /**
     * {@inheritdoc}
     */
    public function description() {
        // We override the description() method in order to change the description
        // text based on the date. On Sunday we only have day old bread.
        if ($this->day == 'Sun') {
            return $this->t("Italian style meatballs drenched in irresistible marinara sauce, served on day old bread.");
        }
        return parent::description();
    }

}