code: def check_dns_txt(domain, prefix, code):
      
      token = '{}={}'.format(prefix, code)
      try:
          for rr in dns.resolver.query(domain, 'TXT'):
              if token in rr.to_text():
                  return True
      except:
          logger.debug('', exc_info=True)
      return False
docs: Validates a domain by checking that {prefix}={code} is present in the TXT DNS record
      of the domain to check.
  
      Returns true if verification suceeded.