protected function _buildItemClasses($item)
    {
        $cls = [
            $this->config('itemClass')
        ];

        if ($this->_isActive($item)) {
            $cls[] = $this->config('itemActiveClass');
        }

        if ($this->_isOpen($item)) {
            $cls[] = $this->config('itemOpenClass');
        }

        return $cls;
    }