@Override
	protected void programDeactivated(Program program) {
		program.removeListener(this);
		memManager.setProgram(null);
		provider.setProgram(null);
	}
Subclass should override this method if it is interested in
close program events.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/memory/MemoryMapPlugin.java