Java 5 provides parameterized types

The code of the add method has been altered. Instead of:
```
public boolean add(Object o)
```
the add method is now documented as:
```
public boolean add(E o)
```

So, we can add elements as before:

0806:        Shape tShape = new Shape(100, 200);
0807:        tList.add(tShape);
0808:        Circle tCircle = new Circle(100, 200, 10);
0809:        tList.add(tCircle);