As shown in Figure 10, a dotted line with a closed, unfilled arrow means realization (or implementation); as we saw in Figure 4, a solid arrow line with a closed, unfilled arrow means inheritance.

如图10所示，一条带有闭合的单向箭头的点线意味着实现(或实施)；正如我们在图4中所见到的，一条带有闭合单向箭头的实线表示继承。