protected function _throw($file, $errorType)
    {
        $this->_value = $file['name'];
        switch($errorType) {
            case Zend_Validate_File_MimeType::FALSE_TYPE :
                $errorType = self::FALSE_TYPE;
                break;
            case Zend_Validate_File_MimeType::NOT_DETECTED :
                $errorType = self::NOT_DETECTED;
                break;
            case Zend_Validate_File_MimeType::NOT_READABLE :
                $errorType = self::NOT_READABLE;
                break;
        }

        $this->_error($errorType);
        return false;
    }