code: async def make_conditional(
              self,
              request_range: Range,
              max_partial_size: Optional[int]=None,
      ) -> None:
          
          self.accept_ranges = "bytes"  # Advertise this ability
          if len(request_range.ranges) == 0:  # Not a conditional request
              return
  
          if request_range.units != "bytes" or len(request_range.ranges) > 1:
              from ..exceptions import RequestRangeNotSatisfiable
              raise RequestRangeNotSatisfiable()
  
          begin, end = request_range.ranges[0]
          try:
              complete_length = await self.response.make_conditional(  # type: ignore
                  begin, end, max_partial_size,
              )
          except AttributeError:
              self.response = self.data_body_class(await self.response.convert_to_sequence())
              return await self.make_conditional(request_range, max_partial_size)
          else:
              self.content_length = self.response.end - self.response.begin  # type: ignore
              if self.content_length != complete_length:
                  self.content_range = ContentRange(
                      request_range.units,
                      self.response.begin, self.response.end - 1,  # type: ignore
                      complete_length,
                  )
                  self.status_code = 206
docs: Make the response conditional to the
  
          Arguments:
              request_range: The range as requested by the request.
              max_partial_size: The maximum length the server is willing
                  to serve in a single response. Defaults to unlimited.