code: def _get_cassandra_config(self):
          
          parts = urlsplit(os.environ.get('CASSANDRA_URI', DEFAULT_URI))
          if parts.scheme != 'cassandra':
              raise RuntimeError(
                  'CASSANDRA_URI scheme is not "cassandra://"!')
  
          _, _, ip_addresses = socket.gethostbyname_ex(parts.hostname)
          if not ip_addresses:
              raise RuntimeError('Unable to find Cassandra in DNS!')
  
          return {
              'contact_points': ip_addresses,
              'port': parts.port or DEFAULT_PORT,
          }
docs: Retrieve a dict containing Cassandra client config params.