code: def stream(self, device_sid=values.unset, limit=None, page_size=None):
          
          limits = self._version.read_limits(limit, page_size)
  
          page = self.page(device_sid=device_sid, page_size=limits['page_size'], )
  
          return self._version.stream(page, limits['limit'], limits['page_limit'])
docs: Streams KeyInstance records from the API as a generator stream.
          This operation lazily loads records as efficiently as possible until the limit
          is reached.
          The results are returned as a generator, so this operation is memory efficient.
  
          :param unicode device_sid: Find all Keys authenticating specified Device.
          :param int limit: Upper limit for the number of records to return. stream()
                            guarantees to never return more than limit.  Default is no limit
          :param int page_size: Number of records to fetch per request, when not set will use
                                the default value of 50 records.  If no page_size is defined
                                but a limit is defined, stream() will attempt to read the
                                limit with the most efficient page size, i.e. min(limit, 1000)
  
          :returns: Generator that will yield up to limit results
          :rtype: list[twilio.rest.preview.deployed_devices.fleet.key.KeyInstance]