DiDom\Query::convertContains PHP Method

    protected static function convertContains($string, $caseSensetive = false)
    {
        if ($caseSensetive) {
            return sprintf('text() = "%s"', $string);
        }
        if (function_exists('mb_strtolower')) {
            return sprintf('php:functionString("mb_strtolower", .) = php:functionString("mb_strtolower", "%s")', $string);
        } else {
            return sprintf('php:functionString("strtolower", .) = php:functionString("strtolower", "%s")', $string);
        }
    }