public function getAvatar($imgOptions = [])
    {
        $imgOptions = ArrayHelper::merge($imgOptions, ['class' => 'img-responsive']);

        if (is_null($this->createdBy))
        {
            return Html::img("http://gravatar.com/avatar/1/?s=50", $imgOptions);
        }

        return Html::img("http://gravatar.com/avatar/{$this->author->id}/?s=50", $imgOptions);
    }