protected function getExistingSlug($slug, $excludeSelf = false)
    {
        $existing = static::where('slug', "$slug");

        if (isset($this->isSlugToggled) && $this->isSlugToggled == true) {
            $existing->where('is_sluggable', true);
        }

        if ($excludeSelf) {
            $existing->where('id', '!=', $this->id);
        }

        return $existing->first() ? true : false;
    }