public void unregisterDataObserver(PersonalDataManagerObserver observer){
  ThreadUtils.assertOnUiThread();
  assert (mDataObservers.size() > 0);
  assert (mDataObservers.contains(observer));
  mDataObservers.remove(observer);
}

public void unregisterDataObserver ( PersonalDataManagerObserver observer ) { ThreadUtils . assertOnUiThread ( ) ; assert ( mDataObservers . size ( ) > 0 ) ; assert ( mDataObservers . contains ( observer ) ) ; mDataObservers . remove ( observer ) ; }
unregisters the provided observer .
