//ConeVolumeComparator.java

import java.util.*;

public class ConeVolumeComparator implements Comparator {

    //***must be this signature.
    //***return 0 if equal, positive if a>b, negative if a<b
    public int compare(Object a, Object b) {
        //***cast the Object parameters to Cones:
        Cone cone1 = (Cone) a;
        Cone cone2 = (Cone) b;
	return cone1.volumeCompareTo(cone2);   //use public method
    }
}