Issue #3270758 by abramm: Rename $plugin variable to make it more obvious what plugin is

    // Alter the form with Omise specific needs.

    $element['#attributes']['class'][] = 'omise-form';

    // Set our key to settings array.

    if (!($this->plugin instanceof OmiseInterface)) {

    $paymentGatewayPlugin = $this->plugin;

    if (!($paymentGatewayPlugin instanceof OmiseInterface)) {

      throw new \InvalidArgumentException('Omise payment method required.');

    }

    // Set our key to settings array.

    $element['#attached']['drupalSettings']['commerceOmise'] = [

      'publicKey' => $this->plugin->getPublicKey(),

      'publicKey' => $paymentGatewayPlugin->getPublicKey(),

    ];

    // To display validation errors.