package java.util;

// Java 8: Definition as a FunctionalInterface
@FunctionalInterface
public interface Comparator<T> {

    // This is THE method in the FunctionalInterface
    int compare(T o1, T o2);

    //Java 8: Static methods with implementation in the interface
     public static <T, U> Comparator<T> comparing(
            Function<? super T, ? extends U> keyExtractor,
            Comparator<? super U> keyComparator)  {
        [...]
    }
     // Java 8: Default implementation in the interface
    default Comparator<T> reversed() {
        return Collections.reverseOrder(this);
    }
}