def _send_message(self, server, body, **params):
        msg = MIMEMultipart('alternative')
        msg.set_charset('utf-8')

        msg['From'] = params['from_addr']
        msg['To'] = ', '.join(params['to'])
        msg['Cc'] = ', '.join(params['cc'])
        msg['Bcc'] = ', '.join(params['bcc'])
        if [None, ''] not in params['subject_prefix']:
            subject = '%s %s' % (params['subject_prefix'],
                                 params['subject'])
        else:
            subject = params['subject']
        msg['Subject'] = Header(subject)

        part = MIMEText(body)
        msg.attach(part)
        server.send_message(msg)
dataset/ETHPy150Open datafolklabs/cement/cement/ext/ext_smtp.py/SMTPMailHandler._send_message/swapped operands of `not in`