public static function createSnippet(string $snptName): ?Snippet
    {
        $snptRoot = AppHelper::getInstance()->getComponentRoot('snippets');
        $snptFile  = $snptRoot.\DIRECTORY_SEPARATOR
            .strtolower($snptName).'.php';
        if (is_readable($snptFile)) {
            return new Snippet($snptFile);
        }
        return null;
    }