code: def get_base_url(use_ssl, instance=None, host=None):
          
  
          if instance is not None:
              host = ("%s.service-now.com" % instance).rstrip('/')
  
          if use_ssl is True:
              return "https://%s" % host
  
          return "http://%s" % host
docs: Formats the base URL either `host` or `instance`
  
          :return: Base URL string