Java - Interface extending itself

Question

I\'ve been using this site for about 6 months now, and its time to ask my first question, because I cant find the answer to this, atleast not an answer that I can understand!

Answer 1

In the first case, you have bounded your generic type parameters to be subtype of the interface itself, whereas, in the second case, you can have any type as generic type parameter. So, they are potentially different declarations.

For example, you can define a reference like:

PositionedVertex

for the 2nd interface type, but not for the 1st one.