public function setType($type)
    {
        switch ($type) {
            case self::TYPE_CSV:
                $this->headers->add(array('Content-Type' => 'text/csv;charset=' . self::UTF_16_LE));
                break;
            case self::TYPE_XLS:
                $this->headers->add(array("Content-Type" => "application/vnd.ms-excel"));
                break;
        }
        $this->type = $type;
    }