public function featuredImageURL($width = null, $height = null, $defaultFeaturedImageURL = '', array $options = [])
    {
        $imageURL = null;
        if ($this->hasFeaturedImage()) {
            if (!$width && !$height) {
                $imageURL = url($this->featuredImage->url) . "?" . strtotime($this->updated_at);
            } else {
                $imageURL = $this->featuredImage->thumb($width, $height, $this->featuredImage, $options);
            }
        }

        if ($imageURL) {
            return $imageURL;
        }
        else if(!$imageURL && $defaultFeaturedImageURL) {
            // return default image if not image is found
            return $defaultFeaturedImageURL;
        }

        return null;
    }