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

			int rows = TestDataKeyModel.ROWCOUNT;
			int half = rows / 2;
			for (int i = 0; i < half; i++) {
				if (monitor.isCancelled()) {
					return;
				}
				accumulator.add((long) i);
			}

			initialLatch.countDown(); // signal we have finished part of the load
			try {
				finishLatch.await(2, TimeUnit.SECONDS);
			}
			catch (InterruptedException e) {
				fail("Interrupted while waiting to load data");
			}

			for (int i = half; i < (half * 2); i++) {
				if (monitor.isCancelled()) {
					return;
				}
				accumulator.add((long) i);
			}
		}
A policy that will initially load half of its data, waiting for the signal to finish
loading the second half.
Ghidra/Framework/Docking/src/test.slow/java/docking/widgets/table/threaded/IncrementalThreadedTableTest.java