package effect.java.generics.item31;

import java.util.HashSet;

import java.util.List;

import java.util.Objects;

import java.util.Set;

import java.util.concurrent.ScheduledFuture;

public class Union {

public static <T> Set<T> union(Set<T> s1, Set<T> s2) {

Set<T> result = new HashSet<>(s1);

result.addAll(s2);

return result;

}

public static <T extends Comparable<? super T>> T max(List<? extends T> c) {

if (c.isEmpty()) {

throw new IllegalArgumentException("Tmpty collection");

}

T result = null;

for (T e : c) {

if (result == null || e.compareTo(result) > 0) {

result = Objects.requireNonNull(e);

}

}

return result;

}

public static void swap(List<?> list, int i, int j) {

swapHelper(list, i, j);

}

private static<E> void swapHelper(List<E> list, int i, int j) {

list.set(i, list.set(j, list.get(i)));

}

public static void main(String[] args) {

List<ScheduledFuture<?>> scheduledFutures = null;

max(scheduledFutures);

}

}