code: public boolean isEmpty() {
  		if (start == null || end == null)
  			return false;
  		int compare = start.compareTo(end);
  		if (compare>0)
  			return true;
  		if (compare == 0 && (!isEndInclusive || !isStartInclusive))
  			return true;
  		return false;
  	}
docs: Checks if the current interval contains no points.
  
  <p>In particular, if the end point is less than the start point, then the interval is
  considered to be empty. There are, however other instances, in which an interval is empty.
  For example, in the class {@link IntegerInterval}, an open interval, whose start and end
  points differ by one, for example the interval (4, 5), is empty, because it contains no integers
  in it. The same interval, however, will <strong>not</strong> be considered empty in the
  {@link DoubleInterval} class, because there are Double numbers within this interval.
  </p>
  
  @return {@code true}, if the current interval is empty or {@code false} otherwise.