titanscssc::listSeparatorForJoin PHP Method

    protected function listSeparatorForJoin($list1, $sep)
    {
        if (is_null($sep)) {
            return $list1[1];
        }
        switch ($this->compileValue($sep)) {
            case "comma":
                return ",";
            case "space":
                return "";
            default:
                return $list1[1];
        }
    }