commerce-8.x-2.8/modules/payment_example/src/Plugin/Commerce/PaymentGateway/OnsiteInterface.php

<?php

namespace Drupal\commerce_payment_example\Plugin\Commerce\PaymentGateway;

use Drupal\commerce_payment\Plugin\Commerce\PaymentGateway\OnsitePaymentGatewayInterface;
use Drupal\commerce_payment\Plugin\Commerce\PaymentGateway\SupportsAuthorizationsInterface;
use Drupal\commerce_payment\Plugin\Commerce\PaymentGateway\SupportsRefundsInterface;
use Drupal\commerce_payment\Plugin\Commerce\PaymentGateway\SupportsUpdatingStoredPaymentMethodsInterface;

/**
 * Provides the interface for the example_onsite payment gateway.
 *
 * The OnsitePaymentGatewayInterface is the base interface which all on-site
 * gateways implement. The other interfaces signal which additional capabilities
 * the gateway has. The gateway plugin is free to expose additional methods,
 * which would be defined below.
 */
interface OnsiteInterface extends OnsitePaymentGatewayInterface, SupportsAuthorizationsInterface, SupportsRefundsInterface, SupportsUpdatingStoredPaymentMethodsInterface {

}