What do I write instead of "TheClass" to make this work? Or is there an alternative way to do it (possibly without making WithName and WithAge generic)?

class Item {
 NeigborList<TheClass> neighbors;
}

class WithName extends Item { // here I want neighbors to be a NeighborList<WithName>
 String name;
 void someMethod() {
  System.out.println(neighbors.nearestTo(this).name);
 }
}

class WithAge extends Item { // here I want neighbors to be a NeighborList<WithAge>
 int age;
 void someOtherMethod() {
  System.out.println(neighbors.nearestTo(this).age);
 }
}