/**
     * Function code to retrieve DFS referrals
     */
    public static final int FSCTL_DFS_GET_REFERRALS = 0x0060194;
    /**
     * Function code to peek at named pipe data without removing it
     */
    public static final int FSCTL_PIPE_PEEK = 0x0011400C;
    /**
     * Function code to wait for a named pipe to become available
     */

     * @return the generated key
     * @throws IOException if an I/O error occurs
     */
    protected abstract long makeKey(Request request) throws IOException;

    /**
     * Peek at the next key without removing it from the input stream
     *
     * @return the next key or null if none available
     * @throws IOException if an I/O error occurs
     */

)

// Max bzip2 concurrency across calls. 50% of GOMAXPROCS.
var bz2Limiter = pbzip2.CreateConcurrencyPool((runtime.GOMAXPROCS(0) + 1) / 2)

func detect(r *bufio.Reader) format {
	z, err := r.Peek(4)
	if err != nil {
		return formatUnknown
	}
	for _, f := range magicHeaders {
		if bytes.Equal(f.header, z[:len(f.header)]) {
			return f.f
		}
	}
	return formatUnknown
}

    } finally {
      monitor.leave();
    }
  }

  @CanIgnoreReturnValue // pushed down from class to method
  @Override
  public @Nullable E peek() {
    Monitor monitor = this.monitor;
    monitor.enter();
    try {
      return q.peek();
    } finally {
      monitor.leave();
    }
  }

  /**

func (c *LRU[K, V]) Contains(key K) (ok bool) {
	c.mu.Lock()
	defer c.mu.Unlock()
	_, ok = c.items[key]
	return ok
}

// Peek returns the key value (or undefined if not found) without updating
// the "recently used"-ness of the key.
func (c *LRU[K, V]) Peek(key K) (value V, ok bool) {
	c.mu.Lock()
	defer c.mu.Unlock()
	var ent *Entry[K, V]
	if ent, ok = c.items[key]; ok {
		// Expired item check

        delegate.put(element)
        editCount++
      }
    }

    override fun iterator() = error("unsupported")

    override fun offer(e: T) = error("unsupported")

    override fun peek(): T = error("unsupported")

    override fun offer(
      element: T,
      timeout: Long,
      unit: TimeUnit,
    ) = error("unsupported")

    override fun take() = error("unsupported")

      this.queue = new ArrayDeque<>();
      queue.add(root);
    }

    @Override
    public boolean hasNext() {
      return !queue.isEmpty();
    }

    @Override
    public T peek() {
      return queue.element();
    }

    @Override
    public T next() {
      T result = queue.remove();
      Iterables.addAll(queue, children(result));
      return result;
    }
  }

      this.queue = new ArrayDeque<>();
      queue.add(root);
    }

    @Override
    public boolean hasNext() {
      return !queue.isEmpty();
    }

    @Override
    public T peek() {
      return queue.element();
    }

    @Override
    public T next() {
      T result = queue.remove();
      Iterables.addAll(queue, children(result));
      return result;
    }
  }

## Attribution

    Object one = new Object();
    assertSame(one, cache.getUnchecked(one));
    assertTrue(segment.recencyQueue.isEmpty());
    assertSame(one, map.get(one));
    assertSame(one, segment.recencyQueue.peek().getKey());
    assertSame(one, cache.getUnchecked(one));
    assertFalse(segment.recencyQueue.isEmpty());
  }

  public void testRecursiveComputation() throws InterruptedException {