assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'b');

    // Iterate again to see if calculation is done again
    assertEqualCharNodes(Iterables.limit(result, 2), "ab");
    assertThat(graph.requestedNodes).containsExactly('a', 'a', 'a', 'b', 'b');
  }

  @Test

   * worker, and then the first thread's call to delegate.execute() returns. Without this counter,
   * it would observe the QUEUING state and set it to QUEUED, and the worker would never be
   * scheduled again for future submissions.
   */
  @GuardedBy("queue")
  private long workerRunCount = 0;

  @RetainedWith private final QueueWorker worker = new QueueWorker();

  /** Use {@link MoreExecutors#newSequentialExecutor} */

 *
 * <p>The {@code Iterable} specification does not make it absolutely clear what should happen on a
 * second invocation, so implementors have made various choices, including:
 *
 * <ul>
 *   <li>returning the same iterator again
 *   <li>throwing an exception of some kind
 *   <li>or the usual, <i>robust</i> behavior, which all known {@link Collection} implementations
 *       have, of returning a new, independent iterator
 * </ul>
 *

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   * prevent us from selecting our {@code SafeAtomicHelper} strategy.
   *
   * <p>Stashing this in a static field avoids loading it over and over again and speeds up test
   * execution significantly.
   */
  private static final ClassLoader NO_ATOMIC_FIELD_UPDATER =
      getClassLoader(
          ImmutableSet.of(
              AtomicIntegerFieldUpdater.class.getName(),

    CharSequenceReader reader = new CharSequenceReader(string);
    assertTrue(reader.markSupported());

    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset and read again
    reader.reset();
    assertEquals(string, readFully(reader));
    assertFullyRead(reader);

    // reset, skip, mark, then read the rest
    reader.reset();
    assertEquals(5, reader.skip(5));

     *   available.
     * 3. We expect the client's get() to throw an InterruptedException.
     * 4. We expect the client thread's interrupt state to be false.
     * 5. The client thread again makes a blocking call to get().
     * 6. Now the result becomes available.
     * 7. We expect get() to return this result.
     * 8. We expect the test thread's interrupt state to be false.
     */

  /**
   * On a concurrent computation that returns null, all threads should get an
   * InvalidCacheLoadException, with the loader only called once. The result should not be cached (a
   * later request should call the loader again).
   */
  private static void testConcurrentLoadingNull(CacheBuilder<Object, Object> builder)
      throws InterruptedException {

    int count = 10;
    final AtomicInteger callCount = new AtomicInteger();

    for (int i = 0; i < 8; i++) {
      limiter.acquire(); // #1
    }
    stopwatch.sleepMillis(500); // #2: to repay for the last acquire
    stopwatch.sleepMillis(4000); // #3: becomes cold again
    for (int i = 0; i < 8; i++) {
      limiter.acquire(); // // #4
    }
    stopwatch.sleepMillis(500); // #5: to repay for the last acquire

            .addValue("value1")
            .add("field2", "value2");
    final String expected = "TestClass{field1=1, value1, field2=value2}";

    assertEquals(expected, helper.toString());
    // Call toString again
    assertEquals(expected, helper.toString());

    // Make sure the cached value is reset when we modify the helper at all
    final String expected2 = "TestClass{field1=1, value1, field2=value2, 2}";