title: JAVA: Generics extend two child classes
body: <p>Say, I have an abstract class A which is extended by child classes B,C &amp; D.
  Is there a way to supply an argument that accepts only B &amp; C using generics.</p>
  
  <p>As far as I know, we can combine a class and interface in generics. But can we combine two child classes?</p>