public function addParamsSelected($fields = null, $props = null)
    {
        if (is_array($fields) && !empty($fields))
        {
            $this->arParams['SELECT_FIELDS'] = array_merge($this->arParams['SELECT_FIELDS'], $fields);
        }

        if (is_array($props) && !empty($props))
        {
            $this->arParams['SELECT_PROPS'] = array_merge($this->arParams['SELECT_PROPS'], $props);
        }
    }