@Override
		public void load(TestDataKeyModel testModel, Accumulator<Long> accumulator,
				TaskMonitor monitor) {

			for (int i = 0; i < testModel.getTestRowCount(); i++) {
				if (monitor.isCancelled()) {
					return;
				}
				accumulator.add((long) i);
				sleep(testModel.getDelayTimeBetweenAddingDataItemsWhileLoading());
			}
		}
A policy that clients can wait for and can block, waiting for client direction.
Ghidra/Framework/Docking/src/test.slow/java/docking/widgets/table/threaded/IncrementalThreadedTableTest.java