Xpressengine\Captcha\CaptchaManager::getDefaultDriver PHP Method

    public function getDefaultDriver()
    {
        return $this->app['config']['captcha.driver'];
    }

 public function testGetAndSetDefaultDriver()
 {
     list($app, $config) = $this->getMocks();
     $instance = new CaptchaManager($app);
     $app->shouldReceive('offsetGet')->with('config')->andReturn($config);
     //        $app->shouldReceive('offsetSet');
     $this->assertEquals('google', $instance->getDefaultDriver());
     $instance->setDefaultDriver('another');
     $this->assertEquals('another', $instance->getDefaultDriver());
 }