code: private boolean isReversed(String s1, String s2) {
  		if (s1 == null || s2 == null) {
  			return false;
  		}
  		return s1.compareToIgnoreCase(s2) > 0;
  	}
docs: Compare the names of the two linkable objects
  and decide if we need to swap their positions.
  For example: isReversed(user, tag) - true; isReversed(tag, user) - false