}

    /**
     * Checks if the crawler threads are daemon threads.
     * @return true if daemon threads, false otherwise.
     */
    public boolean isDaemon() {
        return daemon;
    }

    /**
     * Sets whether the crawler threads should be daemon threads.
     * @param daemon true to make threads daemon, false otherwise.
     */

                    }
                }
            });
        }

        // Start all threads
        for (Thread thread : threads) {
            thread.start();
        }

        // Wait for all threads to complete
        for (Thread thread : threads) {
            thread.join();
        }

        // Verify results
        assertTrue(exceptions.isEmpty());

            });
        }

        for (Thread th : threads) {
            th.start();
        }
        for (Thread th : threads) {
            th.join();
        }
        assertEquals(num, count.get());
        assertEquals(num, valueSet.size());

        Set<String> valueSet2 = Collections.synchronizedSet(new HashSet<>());
        threads = new Thread[threadNum];

            });
        }

        // Start all threads simultaneously
        for (Thread thread : threads) {
            thread.start();
        }

        // Wait for all threads to complete
        for (Thread thread : threads) {
            thread.join();
        }

        // All threads should see the initialized state
        for (boolean result : initResults) {

    /**
     * Interval in milliseconds between crawler thread executions.
     * Used to control the rate at which new crawler threads are started
     * and the frequency of status checks.
     */
    protected long crawlingExecutionInterval = Constants.DEFAULT_CRAWLING_EXECUTION_INTERVAL;

    /**
     * Thread priority for crawler threads.
     * Defaults to normal thread priority.
     */

    for (int i = 0; i < numThreads; i++) {
      threads[i] =
          new Thread() {
            @Override
            public void run() {
              assertSame(Boolean.TRUE, memoizedSupplier.get());
            }
          };
    }
    for (Thread t : threads) {
      t.start();
    }
    for (Thread t : threads) {
      t.join();
    }

    if (thrown.get() != null) {

    for (int i = 0; i < numThreads; i++) {
      threads[i] =
          new Thread() {
            @Override
            public void run() {
              assertSame(Boolean.TRUE, memoizedSupplier.get());
            }
          };
    }
    for (Thread t : threads) {
      t.start();
    }
    for (Thread t : threads) {
      t.join();
    }

    if (thrown.get() != null) {

  }

  /**
   * Add a shutdown hook to wait for thread completion in the given {@link ExecutorService service}.
   * This is useful if the given service uses daemon threads, and we want to keep the JVM from
   * exiting immediately on shutdown, instead giving these daemon threads a chance to terminate
   * normally.
   *
   * @param service ExecutorService which uses daemon threads

                }
            }).start();
        }

        // Signal all threads to start at once
        startLatch.countDown();

        // Wait for all threads to complete
        assertTrue("Threads did not complete in time", doneLatch.await(5, TimeUnit.SECONDS));

        // All threads should fail with the same IOException (project ID is blank)

   * intentionally, so there is no other way to clean up these threads. (The better solution,
   * though, would be to run the tests that use TestThread in separate VMs so that their threads
   * don't hang around during other tests.)
   */
  @Override
  public void tearDown() throws Exception {
    try {
      Thread.class.getMethod("stop").invoke(this);
      join();