doneLatch.countDown();
                }
            }).start();
        }

        startLatch.countDown();
        doneLatch.await();

        // Verify all items were polled exactly once
        assertEquals(itemsPerThread * numThreads, totalPolled.get());
        assertEquals(itemsPerThread * numThreads, allUrls.size());

        urlQueueService.delete(sessionId);
    }

    @Test

    void testHasMoreElements() {
        // Initially should have more elements if error code is 0
        assertTrue(response.hasMoreElements());

        // After calling nextElement once, isPrimary becomes false but hasMore is still true initially
        response.nextElement();

        // Can still have more elements
        assertTrue(response.hasMoreElements());
    }

    @Test

  public TestThread(L lockLikeObject, String threadName) {
    super(threadName);
    this.lockLikeObject = checkNotNull(lockLikeObject);
    start();
  }

  /*
   * TODO: b/318391980 - Once we test only under Java 20 and higher, avoid calling Thread.stop. As
   * of Java 20, it always throws an exception, and as of Java 26, the method does not even exist.
   * For now, we continue using it to clean up under older JDKs.

   * @return a long of a concatenated 8 bytes
   */
  static long load64Safely(byte[] input, int offset, int length) {
    long result = 0;
    // Due to the way we shift, we can stop iterating once we've run out of data, the rest
    // of the result already being filled with zeros.

    // This loop is critical to performance, so please check HashBenchmark if altering it.
    int limit = min(length, 8);

Context timeouts are propagated, and a default timeout of 1 minute is added if none is specified.

There is no cancellation propagation for single payload requests.
When the context is canceled, the request will return at once with an appropriate error.
However, the remote call will not see the cancellation - as can be seen from the 'missing' context on the handler.
The result will be discarded.

### Typed handlers

  @J2ktIncompatible
  @GwtIncompatible // lazyStackTraceIsLazy()
  public void testLazyStackTraceWorksInProd() {
    // TODO(b/64442212): Remove this guard once lazyStackTrace() works in Java 9+.
    Integer javaVersion = Ints.tryParse(JAVA_SPECIFICATION_VERSION.value());
    if (javaVersion != null && javaVersion >= 9) {
      return;
    }

In this case, it would be better to get **one extra server** and run some processes on it so that they all have **enough RAM and CPU time**.

   * {@link LoadingCache#get(Object) get(K)} method instead of this one.
   *
   * <p>Among the improvements that this method and {@code LoadingCache.get(K)} both provide are:
   *
   * <ul>
   *   <li>{@linkplain LoadingCache#get(Object) awaiting the result of a pending load} rather than
   *       starting a redundant one
   *   <li>eliminating the error-prone caching boilerplate

    assertFailure(
        Runnable.class,
        runnable ->
            () -> {
              runnable.run();
              runnable.run();
            },
        "run()",
        "invoked more than once");
  }

  public void testFailsToForwardParameters() {
    assertFailure(Adder.class, FailsToForwardParameters::new, "add(", "Parameter #0");
  }

  public void testForwardsToTheWrongMethod() {

    this.function = checkNotNull(function);
  }

  @Override
  @SuppressWarnings({
    "CatchingUnchecked", // sneaky checked exception
    "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
  })
  public final void run() {
    @RetainedLocalRef ListenableFuture<? extends I> localInputFuture = inputFuture;
    @RetainedLocalRef F localFunction = function;