protected function _getContentTransferEncoding()
    {
        if ($this->transferEncoding) {
            return $this->transferEncoding;
        }

        $charset = strtoupper($this->charset);
        if (in_array($charset, $this->_charset8bit)) {
            return '8bit';
        }

        return '7bit';
    }
protected function _getContentTransferEncoding()
    {
        if ($this->transferEncoding) {
            return $this->transferEncoding;
        }

        $charset = strtoupper($this->charset);
        if (in_array($charset, $this->_charset8bit)) {
            return '8bit';
        }

        return '7bit';
    }
protected function _getContentTransferEncoding ( ) { if ( $ this -> transferEncoding ) { return $ this -> transferEncoding ; } $ charset = strtoupper ( $ this -> charset ) ; if ( in_array ( $ charset , $ this -> _charset8bit ) ) { return '8bit' ; } return '7bit' ; }
Return the Content-Transfer Encoding value based
on the set transferEncoding or set charset.

@return string
Return the Content - Transfer Encoding value based on the set transferEncoding or set charset .