Method Empty!
Part of:
class persistent-set,
class persistent-association-end-set-container,
class persistent-m-n-association-end-set-container,
class persistent-1-n-association-end-set-container,
class persistent-slot-set-container,
class filtered-result-set,
class unique-result-set,
class ordered-result-set,
class grouped-result-set,
class vector-result-set,
class simple-result-set,
class list-result-set(
empty! < abstract-container > )
Removes all items from the container and returns nil.
