code: def _is_wildcard_domain(self, domain):
          
  
          # The * character must be present for a wildcard match, and if there is
          # most than one, it is an invalid wildcard specification
          if domain.count('*') != 1:
              return False
  
          labels = domain.lower().split('.')
  
          if not labels:
              return False
  
          # Wildcards may only appear in the left-most label
          if labels[0].find('*') == -1:
              return False
  
          # Wildcards may not be embedded in an A-label from an IDN
          if labels[0][0:4] == 'xn--':
              return False
  
          return True
docs: Checks if a domain is a valid wildcard according to
          https://tools.ietf.org/html/rfc6125#section-6.4.3
  
          :param domain:
              A unicode string of the domain name, where any U-labels from an IDN
              have been converted to A-labels
  
          :return:
              A boolean - if the domain is a valid wildcard domain