src/View/Helper/Menu.php
protected function normalizeOptions(array $options = [])
    {
        $options = parent::normalizeOptions($options);
        if (isset($options['subLiClassLevel0']) && $options['subLiClassLevel0'] !== null) {
            $options['subLiClassLevel0'] = (string) $options['subLiClassLevel0'];
        } else {
            $options['subLiClassLevel0'] = $this->getSubLiClassLevel0();
        }

        return $options;
    }
protected function normalizeOptions(array $options = [])
    {
        $options = parent::normalizeOptions($options);
        if (isset($options['subLiClassLevel0']) && $options['subLiClassLevel0'] !== null) {
            $options['subLiClassLevel0'] = (string) $options['subLiClassLevel0'];
        } else {
            $options['subLiClassLevel0'] = $this->getSubLiClassLevel0();
        }

        return $options;
    }
Normalizes given render options.

@param  array $options [optional] options to normalize
@return array