I'm not asking for code, not asking for code help, but I can't even figure out what this question is asking me. For those familiar with java could you help me out.

The Collection interface in the Java Collections API defines methods removeAll, addAll, and containsAll. Add these methods to the Collection interface and provide implementations in AbstractCollection
the collections interface defindes the methods, but I have to add them? And AbstractCollection class already implements these methods because it implements the Collection interface. Is he asking me to create my own AbstractCollection class and implement these methods? Is it asking me to use the book's example which doesn't implement them? This book sucks, and I'm not fond of all these interfaces either.