Stackoverflow question

gistfile1.java

abstract class EntityA {
  AssocA myA;
	abstract void meet();
}

abstract class AssocA {
	int something;
	abstract void greet();
}

class AssocAConcrete extends AssocA {
	void greet() {
		System.out.println("hello");
	}
	void salute() {
		System.out.println("I am saluting.")
	}
}

class EntityAConcrete extends EntityA {
	void meet() {
		System.out.println("I am about to meet someone");
		((AssocAConcrete)myA).salute();
	}
}