void addRemove(AddRemoveListItem<T> item) {
		synchronized (addRemoveUpdater) {
			if (pendingJob != null) {
				pendingJob.addRemove(item, getMaxAddRemoveCount());

				// push the updater back to avoid constant reloading
				addRemoveUpdater.updateLater();
				return;
			}

			if (addRemoveWaitList.isEmpty() && thread == null) {
				Swing.runLater(notifyPending);
			}

			addRemoveWaitList.add(item);
			addRemoveUpdater.update();
		}
	}
Tells this update manager that a new row item has been added or removed.  Add/removes never
affect any currently running job.  If a pending job exists, the add/remove will be added
to the pending job.

if no pending jobs exists, the add/remove item will be added to a list to be processed later
when the swing update manager's timer expires.
@param item the add/remove item to process.
Ghidra/Framework/Docking/src/main/java/docking/widgets/table/threaded/ThreadedTableModelUpdateMgr.java