public function createMenu(string $id, string $class): string
    {
        $output = $this->addOpeningNav($id);
        if ($this->options['brand']['name'] !== '') $output .= $this->addBranding();
        if ($this->options['mobile']) $output .= $this->addMobileButton();
        $output .= '<div class="collapse navbar-collapse" id="bootstrapMenu">';
        $output .= $this->createLeftMenu();
        $output .= $this->createRightMenu();
        $output .= '</div>';
        $output .= '</nav>';
        return $output;
    }