Enforcing return type for an class that implements an interface

Question

How do I enforce that the method getFoo() in the implementing class, returns a list of the type of same implementing class.

public interface Bar{
     ....
          


        

Answer 1

I liked yshavit answer best but I could not understand the code. So I will try to write the code as I think it should be.

interface Bar
{
    // stuff
    // don't bother with the getFoo method
}

interface BarUtils
{
    < T extends Bar > List < ? extends T > getFoo ( T bar ) ;
}