offer(e); // never need to block
  }

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

  @CanIgnoreReturnValue // pushed down from class to method
  @Override

 */

package com.google.common.math;

import static java.math.BigInteger.ONE;
import static java.math.BigInteger.ZERO;
import static java.math.RoundingMode.CEILING;
import static java.math.RoundingMode.DOWN;
import static java.math.RoundingMode.FLOOR;
import static java.math.RoundingMode.HALF_DOWN;
import static java.math.RoundingMode.HALF_EVEN;
import static java.math.RoundingMode.HALF_UP;

      }
    } while (System.nanoTime() - deadline < 0);
    throw formatRuntimeException(
        "Latch failed to count down within %d second timeout", timeoutSeconds);
  }

  /**
   * Creates a garbage object that counts down the latch in its finalizer. Sequestered into a
   * separate method to make it somewhat more likely to be unreachable.
   */

   * that enqueued messages were not transmitted.
   *
   * Use this to monitor backpressure and avoid exceeding the 16 MiB outgoing message buffer limit.
   * When that limit is exceeded, the web socket is gracefully shut down.
   */
  fun queueSize(): Long

  /**
   * Attempts to enqueue `text` to be UTF-8 encoded and sent as a the data of a text (type `0x1`)
   * message.
   *

    assertEquals((Integer) 2, it.next());
    it.remove();
    // After this remove, 400 has moved up and 20 down past cursor
    assertTrue("Heap is not intact after remove", mmHeap.isIntact());
    assertEquals((Integer) 10, it.next());
    assertEquals((Integer) 3, it.next());
    it.remove();
    // After this remove, 400 moved down again and 500 up past the cursor
    assertTrue("Heap is not intact after remove", mmHeap.isIntact());

      }
    } while (System.nanoTime() - deadline < 0);
    throw formatRuntimeException(
        "Latch failed to count down within %d second timeout", timeoutSeconds);
  }

  /**
   * Creates a garbage object that counts down the latch in its finalizer. Sequestered into a
   * separate method to make it somewhat more likely to be unreachable.
   */

  private volatile ValueAndCloser<?> valueAndCloser;

  @Override
  protected void tearDown() throws Exception {
    super.tearDown();
    assertWithMessage("finishToValueAndCloserExecutor was shut down")
        .that(shutdownAndAwaitTermination(finishToValueAndCloserExecutor, 10, SECONDS))
        .isTrue();
  }

  public void testFinishToValueAndCloser_throwsIfCalledTwice() throws Exception {

  private volatile ValueAndCloser<?> valueAndCloser;

  @Override
  protected void tearDown() throws Exception {
    super.tearDown();
    assertWithMessage("finishToValueAndCloserExecutor was shut down")
        .that(shutdownAndAwaitTermination(finishToValueAndCloserExecutor, 10, SECONDS))
        .isTrue();
  }

  public void testFinishToValueAndCloser_throwsIfCalledTwice() throws Exception {

    assertThat(record.getMessage())
        .contains("Service FailRunService [FAILED] has failed in the RUNNING state");
  }

  /**
   * Tests that a ServiceManager can be fully shut down if one of its failure listeners is slow or
   * even permanently blocked.
   */
  public void testListenerDeadlock() throws InterruptedException {
    CountDownLatch failEnter = new CountDownLatch(1);

    assertEquals((Integer) 2, it.next());
    it.remove();
    // After this remove, 400 has moved up and 20 down past cursor
    assertTrue("Heap is not intact after remove", mmHeap.isIntact());
    assertEquals((Integer) 10, it.next());
    assertEquals((Integer) 3, it.next());
    it.remove();
    // After this remove, 400 moved down again and 500 up past the cursor
    assertTrue("Heap is not intact after remove", mmHeap.isIntact());