Why is guava AbstractMultiset not publicly available?

Question

I tried to write a class that extends guava AbstractMultiset, but I saw that it was not a public class. Why is this?
Is there any other class that I should extend? Other similar classes that I know ( AbstractCollection, AbstractSetetc.) are publicly available.

Answer 1

I believe the answer was "it was surveillance."

There is a problem with fixing this issue in the problem tracker: http://code.google.com/p/guava-libraries/issues/detail?id=157 . No one objected to this, but this simply did not happen.