void assertThreadStaysAlive(Thread thread, long millis) throws InterruptedException {
    // No need to optimize the failing case via Thread.join.
    delay(millis);
    assertTrue(thread.isAlive());
  }

  /**
   * Checks that the threads do not terminate within the default millisecond delay of {@code
   * timeoutMillis()}.
   */

        // Stop the thread by sending n = -1
        synchronized (w) {
            w.write(new byte[0], -1, out);
        }

        w.join(2000);
        assertFalse(w.isAlive(), "WriterThread should stop after -1 sentinel");
    }

    @Test
    @DisplayName("WriterThread surfaces SmbException via checkException")
    void writerThread_propagates_exception() throws Exception {

      locked.await(1, MINUTES);
    }

    void releaseLockAndFinish() throws InterruptedException {
      finishLatch.countDown();
      this.join(10000);
      assertFalse(this.isAlive());
    }
  }

  public void testReentrantReadWriteLock_implDoesNotExposeShadowedLocks() {
    assertEquals(
        "Unexpected number of public methods in ReentrantReadWriteLock. "

            }
          }
        };
    waiter.start();
    awaitTimedWaiting(waiter);
    service.shutdown();
    Uninterruptibles.joinUninterruptibly(waiter, 10, SECONDS);
    if (waiter.isAlive()) {
      waiter.interrupt();
      fail("awaitTermination failed to trigger after shutdown()");
    }
  }

  /** Wait for the given thread to reach the {@link State#TIMED_WAITING} thread state. */

   * instance that is ready to receive data. Example:
   *
   * {@snippet :
   * HashFunction hf = Hashing.md5();
   * HashCode hc = hf.newHasher()
   *     .putLong(id)
   *     .putBoolean(isActive)
   *     .hash();
   * }
   */
  Hasher newHasher();

  /**
   * Begins a new hash code computation as {@link #newHasher()}, but provides a hint of the expected

   * instance that is ready to receive data. Example:
   *
   * {@snippet :
   * HashFunction hf = Hashing.md5();
   * HashCode hc = hf.newHasher()
   *     .putLong(id)
   *     .putBoolean(isActive)
   *     .hash();
   * }
   */
  Hasher newHasher();

  /**
   * Begins a new hash code computation as {@link #newHasher()}, but provides a hint of the expected

            }
          }
        };
    waiter.start();
    awaitTimedWaiting(waiter);
    service.shutdown();
    Uninterruptibles.joinUninterruptibly(waiter, 10, SECONDS);
    if (waiter.isAlive()) {
      waiter.interrupt();
      fail("awaitTermination failed to trigger after shutdown()");
    }
  }

  /** Wait for the given thread to reach the {@link State#TIMED_WAITING} thread state. */

      this.loading = loading;
    }

    @Override
    public boolean isLoading() {
      return loading;
    }

    @Override
    public boolean isActive() {
      return !loading;
    }

    @Override
    public V waitForValue() {
      return get();
    }

    @Override
    public void notifyNewValue(V newValue) {}

      this.loading = loading;
    }

    @Override
    public boolean isLoading() {
      return loading;
    }

    @Override
    public boolean isActive() {
      return !loading;
    }

    @Override
    public V waitForValue() {
      return get();
    }

    @Override
    public void notifyNewValue(V newValue) {}

        } catch (final Throwable t) {
            logger.error("Crawler terminated unexpectedly.", t);
            exitCode = Constants.EXIT_FAIL;
        } finally {
            if (commandThread != null && commandThread.isAlive()) {
                commandThread.interrupt();
            }
            if (systemMonitorTask != null) {
                systemMonitorTask.cancel();
            }
            if (hotThreadMonitorTask != null) {