One errata I guess. 3rd review question in chapter 7, I thing D is also correct answer: Line w4 causes compile time error. Future's get() method may throw checked exception and it is not handled, nor declared anywhere in the code.
The code snippet for question 3 in chapter 7 does not start at line 1, as there are no line numbers. Since it doesn't start at line 1, we can assume that the imports and Class definition are present and are correct, thus w4 won't cause a compile time error.
OK, maybe not errata exactly...
With correct class definition and imports I agree. But it is still a bit confusing to assume that method definition throws checked exception. This way I could assume lots of things.