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//: polymorphism/CovariantReturn.java

class Grain {

public String toString() { return "Grain"; }

}

class Wheat extends Grain {

public String toString() { return "Wheat"; }

}

class Mill {

Grain process() { return new Grain(); }

}

class WheatMill extends Mill {

Wheat process() { return new Wheat(); }

}

public class CovariantReturn {

public static void main(String[] args) {

Mill m = new Mill();

Grain g = m.process();

System.out.println(g);

m = new WheatMill();

g = m.process();

System.out.println(g);

}

} /* Output:

Grain

Wheat

*///:~