public function get_icon_system() {

        // Getting all the candidate functions.
        $system = false;
        if (isset($this->iconsystem) && \core\output\icon_system::is_valid_system($this->iconsystem)) {
            return $this->iconsystem;
        }
        foreach ($this->parent_configs as $parent_config) {
            if (isset($parent_config->iconsystem) && \core\output\icon_system::is_valid_system($parent_config->iconsystem)) {
                return $parent_config->iconsystem;
            }
        }
        return \core\output\icon_system::STANDARD;
    }