Java 5 provides parameterized types

However, if our code inadvertently adds a value of the wrong type:
```
0814:        tList.add("hello world");
```

then that statement will fail to compile:

0819: ListShape.java:16: cannot find symbol
0820: symbol  : method add(java.lang.String)
0821: location: interface java.util.List<Shape>
0822:        tList.add("hello world");
0823:             ^

This is a lot better than crashing with a ClassCastException.