Use of the default package is very strongly discouraged.
It used to be the case that you could import a class from the default package into a named package as shown, but it was never explicitly stated in the
Java Language Spec that this was legal. Recent versions of the spec state that it is
illegal, and recent versions of javac now reject this syntax. As a result, doing what you need to do is now
not possible.
Solution: don't use the default package.