@Override
	void doRedo(boolean notify) throws IOException {
		if (canRedo()) {
			SynchronizedTransaction t = redoList.removeLast();
			undoList.addLast(t);
			t.redo();
			if (notify) {
				notifyUndoableListeners();
			}
		}
	}
Returns the undo stack depth.
(The number of items on the undo stack)
This method is for JUnits.
@return the undo stack depth
Ghidra/Framework/Project/src/main/java/ghidra/framework/data/SynchronizedTransactionManager.java