The methods PackageDoc.annotations() and Parameter.annotations()
cannot yet be implemented: javac does not yet provide the functionality
upon which to implement them. These are known javac bugs and will be
fixed eventually.

Currently these methods throw UnsupportedOperationException("TBD").
At the time this was coded, it was expected that javac would be fixed
in time to provide proper implementations for Tiger. Since we're coming
up on beta freeze, it would be prudent to hedge our bets and provide a
more informative message such as:
UnsupportedOperationException("Not implemented in this release").