private void addTransactionListener(Program program) {
		if (program != null) {
			program.addTransactionListener(transactionListener);
		}
	}
Abstract base class for the undo and redo actions. These actions add a listener to the
current context program in order to know when to update their enabled state and description.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/AbstractUndoRedoAction.java