public static function showRoutes($moduleUid = '', $app = null, $echo = false)
    {
        if (empty($app)) {
            $app = Yii::$app;
        }
        $urlMan = $app->urlManager;
        $result = '';
        foreach ($urlMan->rules as $rule) {
            if (empty($moduleUid)) {
                $result .= static::showRoute($rule);
            } else {
                switch ($rule::className()) {
                    case GroupUrlRule::className():
                        foreach ($rule->rules as $singleRule) {
                            if (0 === strpos($singleRule->route, $moduleUid)) {
                                $result .= static::showRoute($rule); // will show all rules from group
                                break;
                            }
                        }
                        break;
                    case RestUrlRule::className():
                        if (is_array($rule->controller)) {
                            $urlPrefix = array_keys($rule->controller)[0];
                            $controller = $rule->controller[$urlPrefix];
                        } else {
                            $controller = $rule->controller;
                        }
                        if (0 === strpos($controller, $moduleUid)) {
                            $result .= static::showRoute($rule);
                        }
                        break;
                    default:
                        if (0 === strpos($rule->route, $moduleUid)) {
                            $result .= static::showRoute($rule);
                        }
                        break;
                }
           }
        }
        if ($echo) {
           echo $result;
        } else {
           return $result;
        }
    }