private void prepareGroup(GTaskGroup taskGroup) {
		List<GScheduledTask> tasks = taskGroup.getTasks();
		priorityQ.addAll(tasks);
		if (taskGroup.wantsNewTransaction()) {
			closeTransaction();
		}
		openTransaction(taskGroup.getDescription());
		runningGroup = taskGroup;
		notifyGroupStarted(taskGroup);
	}
Cancels all scheduled groups and tasks. The TaskMonitor for
the currently running task will be cancelled, but the task will continue to run until it
checks the monitor.
Ghidra/Framework/Project/src/main/java/ghidra/framework/task/GTaskManager.java