@CanIgnoreReturnValue
  @Override
  public @Nullable E poll() {
    final Monitor monitor = this.monitor;
    if (monitor.enterIf(notEmpty)) {
      try {
        return extract();
      } finally {
        monitor.leave();
      }
    } else {
      return null;
    }
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable E poll(long timeout, TimeUnit unit) throws InterruptedException {

      int read = (reader != null) ? reader.read(buf, 0, buf.length) : readable.read(cbuf);
      if (read == -1) {
        lineBuf.finish();
        break;
      }
      lineBuf.add(buf, 0, read);
    }
    return lines.poll();
  }

 *     .maximumSize(1000)
 *     .create();
 * }</pre>
 *
 * <p>As a {@link Queue} it functions exactly as a {@link PriorityQueue}: its head element -- the
 * implicit target of the methods {@link #peek()}, {@link #poll()} and {@link #remove()} -- is
 * defined as the <i>least</i> element in the queue according to the queue's comparator. But unlike
 * a regular priority queue, the methods {@link #peekLast}, {@link #pollLast} and {@link

    return null
  }

  private fun awaitTcpConnect(
    timeout: Long,
    unit: TimeUnit,
  ): ConnectResult? {
    if (tcpConnectsInFlight.isEmpty()) return null

    val result = connectResults.poll(timeout, unit) ?: return null

    tcpConnectsInFlight.remove(result.plan)

    return result
  }

  private fun cancelInFlightConnects() {
    for (plan in tcpConnectsInFlight) {
      plan.cancel()

        loadFinalizer(new SystemLoader(), new DecoupledLoader(), new DirectLoader());
    startFinalizer = getStartFinalizer(finalizer);
  }

  /** The actual reference queue that our background thread will poll. */
  final ReferenceQueue<Object> queue;

  final PhantomReference<Object> frqRef;

  /** Whether or not the background thread started successfully. */
  final boolean threadStarted;

            UrlQueue urlQueue;
            while ((urlQueue = urlQueueService.poll(sessionId1)) != null) {
                assertTrue(urlQueue.getUrl().startsWith(url1));
            }
            while ((urlQueue = urlQueueService.poll(sessionId2)) != null) {
                assertTrue(urlQueue.getUrl().startsWith(url2));
            }

    }


    private void cleanup () {
        synchronized ( this.connections ) {
            SmbTransportImpl trans;
            while ( ( trans = this.toRemove.poll() ) != null ) {

                if ( log.isDebugEnabled() ) {
                    log.debug("Removing transport connection " + trans + " (" + System.identityHashCode(trans) + ")");
                }

    assertFalse(queue.remove("hi"));
    assertEquals(0, queue.size());

    assertThrows(NoSuchElementException.class, () -> queue.element());

    assertNull(queue.peek());
    assertNull(queue.poll());
    assertThrows(NoSuchElementException.class, () -> queue.remove());
  }

  public void testRemainingCapacity_maxSize0() {
    EvictingQueue<String> queue = EvictingQueue.create(0);

        assertFalse(map.containsValue(valueOne));
        assertNull(map.get(keyOne));
        assertEquals(1, map.size());
        assertNull(segment.getKeyReferenceQueueForTesting().poll());
      }
    }
  }

  public void testDrainValueReferenceQueueOnWrite() {
    for (MapMaker maker : allWeakValueStrengthMakers()) {

        assertFalse(map.containsValue(valueOne));
        assertNull(map.get(keyOne));
        assertEquals(1, map.size());
        assertNull(segment.getKeyReferenceQueueForTesting().poll());
      }
    }
  }

  public void testDrainValueReferenceQueueOnWrite() {
    for (MapMaker maker : allWeakValueStrengthMakers()) {