// there are no queues; otherwise the requests are tracked in the queues.
	requestsExecutingSet sets.Set[*request]

	// totSeatsInUse is the number of total "seats" in use by all the
	// request(s) that are currently executing in this queueset.
	totSeatsInUse int

	// totSeatsWaiting is the sum, over all the waiting requests, of their
	// max width.
	totSeatsWaiting int

				totSeatsInUse:            test.totSeatsInUse,
				qCfg:                     fq.QueuingConfig{Name: "TestSelectQueueLocked/" + test.name},
				dCfg: fq.DispatchingConfig{
					ConcurrencyLimit: test.concurrencyLimit,
				},
				queues: test.queues,
			}

			t.Logf("QS: robin index=%d, seats in use=%d limit=%d", qs.robinIndex, qs.totSeatsInUse, qs.dCfg.ConcurrencyLimit)