Webiny\Component\Mailer\Bridge\SwiftMailer\Message::setContentTransferEncoding PHP Method

    public function setContentTransferEncoding($encoding)
    {
        switch ($encoding) {
            case '7bit':
                $encoder = \Swift_Encoding::get7BitEncoding();
                break;
            case '8bit':
                $encoder = \Swift_Encoding::get8BitEncoding();
                break;
            case 'base64':
                $encoder = \Swift_Encoding::getBase64Encoding();
                break;
            case 'qp':
                $encoder = \Swift_Encoding::getQpEncoding();
                break;
            default:
                throw new SwiftMailerException('Invalid encoding name provided.
												Valid encodings are [7bit, 8bit, base64, qp].');
                break;
        }
        $this->message->setEncoder($encoder);
        return $this;
    }

 /**
  * @dataProvider messageProvider
  *
  * @param Message $message
  *
  * @expectedException \Webiny\Component\Mailer\Bridge\SwiftMailer\SwiftMailerException
  */
 public function testSetContentTransferEncodingException($message)
 {
     $message->setContentTransferEncoding('doesnt exist');
 }