The override is here only because it is needed or the implementation of SensorEventListener wont compile.  I didn't have an output there because I don't know how this may behave on some Androids... it isn't really something that I could see as being useful to be notified, and I did only see it happen once or twice on my tests when I did have output there.  Between the lack of usefulness, nothing to really act upon, and potential for spamming on some devices possible, I'd like to leave it empty if that's OK with you.