public function createCaptchaAction()
{
$ca = Yii::$app->createController($this->captchaAction);
if ($ca !== false) {
/* @var $controller \yii\base\Controller */
list($controller, $actionID) = $ca;
$action = $controller->createAction($actionID);
if ($action !== null) {
return $action;
}
}
throw new InvalidConfigException('Invalid CAPTCHA action ID: ' . $this->captchaAction);
}