protected function _setPathSegmentSeparator($separator)
    {
        if (
            !($separator instanceof Stringable) &&
            !is_string($separator) &&
            !is_null($separator)
        ) {
            throw $this->_createInvalidArgumentException($this->__('Invalid path segment separator'), null, null, $separator);
        }

        $this->pathSegmentSeparator = $separator;
    }