private TaskMonitor getMonitor(GTree tree) {
		if (tree == null) {
			return TaskMonitor.DUMMY;
		}
		return tree.getThreadLocalMonitor();
	}
Subclass must implement this method to generate their children. This operation will always be
performed in a background thread (i.e. Not the swing thread)

@param monitor a TaskMonitor for reporting progress and cancel notification.
@return the list of children for this node.
@throws CancelledException if the monitor is cancelled
Ghidra/Framework/Docking/src/main/java/docking/widgets/tree/GTreeSlowLoadingNode.java