`Well, there was Mystery,' the Mock Turtle replied, counting
off the subjects on his flappers, `--Mystery, ancient and modern,
with Seaography:  then Drawling--the Drawling-master was an old
conger-eel, that used to come once a week:  HE taught us
Drawling, Stretching, and Fainting in Coils.'

  `What was THAT like?' said Alice.

  `Well, I can't show it you myself,' the Mock Turtle said:  `I'm
too stiff.  And the Gryphon never learnt it.'

      ReferenceEntry<?, ?> originalHead = segment.accessQueue.peek();
      @SuppressWarnings("unchecked")
      ReferenceEntry<Integer, Integer> entry = (ReferenceEntry<Integer, Integer>) originalHead;
      operation.accept(entry);
      drainRecencyQueue(segment);

      assertNotSame(originalHead, segment.accessQueue.peek());
      assertEquals(cache.size(), accessQueueSize(cache));
    }
  }

        "Should be able to peek() middle element multiple times", "B", peekingIterator.peek());
    assertEquals(
        "next() should still return middle element after peeking", "B", peekingIterator.next());

    assertEquals("Should be able to peek() at last element", "C", peekingIterator.peek());
    assertEquals(
        "Should be able to peek() last element multiple times", "C", peekingIterator.peek());
    assertEquals(

      this.strong = true;
      return this;
    }

    /**
     * Instructs the {@link InternerBuilder} to build a weak interner.
     *
     * @see Interners#newWeakInterner()
     */
    @GwtIncompatible("java.lang.ref.WeakReference")
    public InternerBuilder weak() {
      this.strong = false;
      return this;
    }

    /**

  }

  @CanIgnoreReturnValue
  @Override
  @ParametricNullness
  public E remove() {
    return delegate().remove();
  }

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

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

  /**

   *   <li>clearing weak references to unreachable referents
   *   <li>enqueuing weak references to unreachable referents in their reference queue
   * </ul>
   */
  @DoNotMock("Implement with a lambda")
  public interface FinalizationPredicate {
    boolean isDone();
  }

  /**
   * Waits until the given weak reference is cleared, invoking the garbage collector as necessary to

          }
        };

    assertEquals(0, (int) iter.peek());
    assertEquals(0, (int) iter.peek());
    assertTrue(iter.hasNext());
    assertEquals(0, (int) iter.peek());
    assertEquals(0, (int) iter.next());

    assertEquals(1, (int) iter.peek());
    assertEquals(1, (int) iter.next());

    try {
      iter.peek();
      fail("peek() should throw NoSuchElementException at end");

   * contract of {@link PeekingIterator#peek()}.
   *
   * <p>Implementations of {@code AbstractIterator} that wish to expose this functionality should
   * implement {@code PeekingIterator}.
   */
  @ParametricNullness
  public final T peek() {
    if (!hasNext()) {
      throw new NoSuchElementException();
    }

    public boolean remove(Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.remove(object);
    }

    @Override
    public @Nullable E peek() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.peek();
    }

    @Override
    public E element() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.element();
    }

    @Override

import com.google.common.annotations.J2ktIncompatible;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import javax.annotation.CheckForNull;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee