*       be thrown using {@code Throwable.addSuppressed(Throwable)}.
 *   <li><b>Java 6:</b> Exceptions are suppressed by logging them instead.
 * </ul>
 *
 * @author Colin Decker
 * @since 14.0
 */
// Coffee's for {@link Closer closers} only.
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class Closer implements Closeable {

      int k, Comparator<? super T> comparator) {
    checkNonnegative(k, "k");
    checkNotNull(comparator);
    return Collector.of(
        () -> TopKSelector.<T>least(k, comparator),
        TopKSelector::offer,
        TopKSelector::combine,
        TopKSelector::topK,
        Collector.Characteristics.UNORDERED);
  }

  /**

    for (int i = 0; i < 10; i++) {
      top.offer(i);
    }
    assertThat(top.topK()).isEmpty();
  }

  public void testNoElementsOffered() {
    TopKSelector<Integer> top = TopKSelector.least(10);
    assertThat(top.topK()).isEmpty();
  }

  public void testOfferedFewerThanK() {
    TopKSelector<Integer> top = TopKSelector.least(10);
    top.offer(3);
    top.offer(5);
    top.offer(2);

 * tailored to that use case.
 *
 * <p>This uses the same efficient implementation as {@link Ordering#leastOf(Iterable, int)},
 * offering expected O(n + k log k) performance (worst case O(n log k)) for n calls to {@link
 * #offer} and a call to {@link #topK}, with O(k) memory. In comparison, quickselect has the same
 * asymptotics but requires O(n) memory, and a {@code PriorityQueue} implementation takes O(n log

    SortedMap<Integer, AtomicInteger> replica = Maps.newTreeMap();
    assertTrue("Empty heap should be OK", mmHeap.isIntact());
    for (int i = 0; i < heapSize; i++) {
      int randomInt = random.nextInt();
      mmHeap.offer(randomInt);
      insertIntoReplica(replica, randomInt);
    }
    assertIntact(mmHeap);
    assertEquals(heapSize, mmHeap.size());
    int currentHeapSize = heapSize;

    @Override
    public E element() {
      synchronized (mutex) {
        return delegate().element();
      }
    }

    @Override
    public boolean offer(E e) {
      synchronized (mutex) {
        return delegate().offer(e);
      }
    }

    @Override
    @CheckForNull
    public E peek() {
      synchronized (mutex) {
        return delegate().peek();
      }

    for (int i = 0; i < 10; i++) {
      top.offer(i);
    }
    assertThat(top.topK()).isEmpty();
  }

  public void testNoElementsOffered() {
    TopKSelector<Integer> top = TopKSelector.least(10);
    assertThat(top.topK()).isEmpty();
  }

  public void testOfferedFewerThanK() {
    TopKSelector<Integer> top = TopKSelector.least(10);
    top.offer(3);
    top.offer(5);
    top.offer(2);

    SortedMap<Integer, AtomicInteger> replica = Maps.newTreeMap();
    assertTrue("Empty heap should be OK", mmHeap.isIntact());
    for (int i = 0; i < heapSize; i++) {
      int randomInt = random.nextInt();
      mmHeap.offer(randomInt);
      insertIntoReplica(replica, randomInt);
    }
    assertIntact(mmHeap);
    assertEquals(heapSize, mmHeap.size());
    int currentHeapSize = heapSize;