code: def list_findings(
          self,
          parent,
          filter_=None,
          order_by=None,
          read_time=None,
          field_mask=None,
          page_size=None,
          retry=google.api_core.gapic_v1.method.DEFAULT,
          timeout=google.api_core.gapic_v1.method.DEFAULT,
          metadata=None,
      ):
          if "list_findings" not in self._inner_api_calls:
              self._inner_api_calls[
                  "list_findings"
              ] = google.api_core.gapic_v1.method.wrap_method(
                  self.transport.list_findings,
                  default_retry=self._method_configs["ListFindings"].retry,
                  default_timeout=self._method_configs["ListFindings"].timeout,
                  client_info=self._client_info,
              )
          request = securitycenter_service_pb2.ListFindingsRequest(
              parent=parent,
              filter=filter_,
              order_by=order_by,
              read_time=read_time,
              field_mask=field_mask,
              page_size=page_size,
          )
          if metadata is None:
              metadata = []
          metadata = list(metadata)
          try:
              routing_header = [("parent", parent)]
          except AttributeError:
              pass
          else:
              routing_metadata = google.api_core.gapic_v1.routing_header.to_grpc_metadata(
                  routing_header
              )
              metadata.append(routing_metadata)
          iterator = google.api_core.page_iterator.GRPCIterator(
              client=None,
              method=functools.partial(
                  self._inner_api_calls["list_findings"],
                  retry=retry,
                  timeout=timeout,
                  metadata=metadata,
              ),
              request=request,
              items_field="findings",
              request_token_field="page_token",
              response_token_field="next_page_token",
          )
          return iterator