private List<GTreeNode> generateChildrenNow(TaskMonitor monitor) {
		try {
			return generateChildren(monitor);
		}
		catch (CancelledException e) {
			return null;
		}
	}
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