if (source.isEmpty()) {
        throw PermittedMetaException.NSEE;
      }

      destination.push(source.pop());
      stackWithLastReturnedElementAtTop = destination;
      return destination.peek();
    }

    private void throwIfInvalid(IteratorFeature methodFeature) {
      if (!features.contains(methodFeature)) {
        if (stackWithLastReturnedElementAtTop == null) {

 * they end up depending on <i>other</i> existing poor-quality {@code hashCode} implementations,
 * including those in many JDK classes.
 *
 * <p>{@code Object.hashCode} implementations tend to be very fast, but have weak collision
 * prevention and <i>no</i> expectation of bit dispersion. This leaves them perfectly suitable for
 * use in hash tables, because extra collisions cause only a slight performance hit, while poor bit

 * they end up depending on <i>other</i> existing poor-quality {@code hashCode} implementations,
 * including those in many JDK classes.
 *
 * <p>{@code Object.hashCode} implementations tend to be very fast, but have weak collision
 * prevention and <i>no</i> expectation of bit dispersion. This leaves them perfectly suitable for
 * use in hash tables, because extra collisions cause only a slight performance hit, while poor bit

    Iterator<Integer> consumingIterator = Iterables.consumingIterable(queue).iterator();

    assertEquals(5, queue.peek().intValue());
    assertEquals(5, consumingIterator.next().intValue());

    assertEquals(14, queue.peek().intValue());
    assertTrue(consumingIterator.hasNext());
    assertTrue(queue.isEmpty());
  }

  public void testConsumingIterable_noIteratorCall() {

   * a modest limit on `byteCount`, such as 1 MiB.
   */
  @Throws(IOException::class)
  fun peekBody(byteCount: Long): ResponseBody {
    val peeked = body.source().peek()
    val buffer = Buffer()
    peeked.request(byteCount)
    buffer.write(peeked, minOf(byteCount, peeked.buffer.size))
    return buffer.asResponseBody(body.contentType(), buffer.size)
  }

    monitor.enterWhen(notEmpty);
    try {
      return extract();
    } finally {
      monitor.leave();
    }
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable E peek() {
    final Monitor monitor = this.monitor;
    if (monitor.enterIf(notEmpty)) {
      try {
        return items[takeIndex];
      } finally {
        monitor.leave();
      }
    } else {

      while (peekingItr.hasNext()) {
        Range<C> range = peekingItr.next();
        while (peekingItr.hasNext()) {
          Range<C> nextRange = peekingItr.peek();
          if (range.isConnected(nextRange)) {
            checkArgument(
                range.intersection(nextRange).isEmpty(),
                "Overlapping ranges not permitted but found %s overlapping %s",

        return Equivalence.equals();
      }
    },

    SOFT {
      @Override
      Equivalence<Object> defaultEquivalence() {
        return Equivalence.identity();
      }
    },

    WEAK {
      @Override
      Equivalence<Object> defaultEquivalence() {
        return Equivalence.identity();
      }
    };

    abstract Equivalence<Object> defaultEquivalence();
  }

  /**

      if (source.isEmpty()) {
        throw PermittedMetaException.NSEE;
      }

      destination.push(source.pop());
      stackWithLastReturnedElementAtTop = destination;
      return destination.peek();
    }

    private void throwIfInvalid(IteratorFeature methodFeature) {
      if (!features.contains(methodFeature)) {
        if (stackWithLastReturnedElementAtTop == null) {

   */
  @GwtIncompatible // java.lang.ref.WeakReference
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> weakKeys() {
    return setKeyStrength(Strength.WEAK);
  }

  @CanIgnoreReturnValue
  CacheBuilder<K, V> setKeyStrength(Strength strength) {
    checkState(keyStrength == null, "Key strength was already set to %s", keyStrength);