Need to verify proper usage of all question mark type generic declarations

[RuinedSubmartingale]

I'm pretty sure I've used <? super T> in places where it should be <? extends T> (or perhaps not needed at all)

Relevant mnemonic: PECS (Producer Extends, Consumer Super)

see following resources:
http://stackoverflow.com/questions/591004/generics-super-t
http://stackoverflow.com/questions/4343202/difference-between-super-t-and-extends-t-in-java