"? extends" is a cool question because even if you know nothing theoretical about generics, you can figure it out with a few hints because it does have an actua

"? extends" is a cool question because even if you know nothing theoretical about generics, you can figure it out with a few hints because it does have an actual underlying reason. Or you can't - even with massive hinting some people are just afraid to guess and reason. So it's a nice test.