_objectManager = $objectManager; } /** * Get captcha instance * * @param string $captchaType * @param string $formId * @return \Magento\Captcha\Model\CaptchaInterface * @throws \InvalidArgumentException */ public function create($captchaType, $formId) { $className = 'Magento\Captcha\Model\\' . ucfirst($captchaType); $instance = $this->_objectManager->create($className, ['formId' => $formId]); if (!$instance instanceof \Magento\Captcha\Model\CaptchaInterface) { throw new \InvalidArgumentException( $className . ' does not implement \Magento\Captcha\Model\CaptchaInterface' ); } return $instance; } }