public void addPosition(Position position) {
		if(position == null)
			throw new NullPointerException("null cannot be added as a Position");
		
		System.out.println("TEST1: " + otherPositions.size());
		
		otherPositions.add(position);
		
		System.out.println("TEST2: " + otherPositions.size());
		
		if (otherPositions.size() > 2) {
			Position newHeadPosition = otherPositions.remove(0);
			setPosition(newHeadPosition);
		}
		
		System.out.println("TEST3: " + otherPositions.size());
	}