* not in {@link #nextElements}, this method throws an {@link UnknownElementException}.
     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to

     * not in {@link #nextElements}, this method throws an {@link UnknownElementException}.
     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to

        clearValueReferenceQueue();
      }
    }

    void clearKeyReferenceQueue() {
      while (keyReferenceQueue.poll() != null) {}
    }

    void clearValueReferenceQueue() {
      while (valueReferenceQueue.poll() != null) {}
    }

    // recency queue, shared by expiration and eviction

    /**

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

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

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

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

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

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

        // Clean up all pooled regions
        RdmaMemoryRegion region;

        while ((region = availableSendRegions.poll()) != null) {
            region.close();
            totalReleased.incrementAndGet();
        }

        while ((region = availableReceiveRegions.poll()) != null) {
            region.close();
            totalReleased.incrementAndGet();
        }

        clearValueReferenceQueue();
      }
    }

    void clearKeyReferenceQueue() {
      while (keyReferenceQueue.poll() != null) {}
    }

    void clearValueReferenceQueue() {
      while (valueReferenceQueue.poll() != null) {}
    }

    // recency queue, shared by expiration and eviction

    /**

    assertEquals(1, (int) mmHeap.peek());
    assertEquals(1, (int) mmHeap.poll());
    assertEquals(3, (int) mmHeap.peekLast());
    assertEquals(2, (int) mmHeap.peek());
    assertEquals(2, (int) mmHeap.poll());
    assertEquals(3, (int) mmHeap.peekLast());
    assertEquals(3, (int) mmHeap.peek());
    assertEquals(3, (int) mmHeap.poll());
    assertThat(mmHeap.peekLast()).isNull();
    assertThat(mmHeap.peek()).isNull();

        socket.sink.use {
          while (true) {
            val action = actions.poll() ?: break
            action(socket)
          }
        }
      }
      return@FutureTask null
    }
  }

  /** Returns once all stream actions complete successfully. */
  fun awaitSuccess() {
    val futureTask =
      results.poll(5, TimeUnit.SECONDS)
        ?: throw AssertionError("no onRequest call received")

                return;
            }
            response = r;

            executeCallbacks = new ArrayList<>(doneCallbacks.size());
            Consumer<RESPONSE> callback;
            while ((callback = doneCallbacks.poll()) != null) {
                executeCallbacks.add(callback);
            }
        }
        if (executeCallbacks.size() > 0) {
            try {