latch = new CountDownLatch(1);
    future = createListenableFuture(Boolean.TRUE, null, latch);
  }

  @Override
  protected void tearDown() throws Exception {

    // Make sure we have no waiting threads.
    latch.countDown();
  }

  /** Constructs a listenable future with a value available after the latch has counted down. */
  protected abstract <V> ListenableFuture<V> createListenableFuture(

     */
    public String execute() {
        try {
            final long count = ComponentUtil.getThumbnailManager().purge(getExpiry());
            return "Deleted " + count + " thumbnail files.";
        } catch (final Exception e) {
            logger.error("Failed to purge thumbnails.", e);
            return e.getMessage();
        }
    }

    /**
     * Gets the expiration time for thumbnails.
     *

 * to create an exception instance with a message and an optional cause.
 *
 * <p>Usage examples:</p>
 * <pre>
 *     throw new CurlException("Error message");
 *     throw new CurlException("Error message", cause);
 * </pre>
 *
 * @see RuntimeException
 */
public class CurlException extends RuntimeException {

    private static final long serialVersionUID = 1L;

    /**

 * <p>
 * Example usage:
 * <pre>
 * public class CustomPackagingProvider implements PackagingProvider {
 *     public Collection&lt;Packaging&gt; provides() {
 *         return Arrays.asList(
 *             packaging("docker-image"),
 *             packaging("flatpak")
 *         );
 *     }
 * }
 * </pre>
 *
 * @see org.apache.maven.api.Packaging

 * annotated with LargeTest.
 *
 * <p>Why use a custom annotation instead of {@code android.test.suitebuilder.annotation.Suppress}?
 * I'm not completely sure that this is the right choice, but it has various advantages:
 *
 * <ul>
 *   <li>An annotation named just "Suppress" might someday be treated by a non-Android tool as a

 * <p>
 * Implementations of this interface will be discovered through the Java ServiceLoader mechanism
 * and their provided lifecycles will be available throughout the Maven build process.
 * <p>
 * Example usage:
 * <pre>
 * public class CustomLifecycleProvider implements LifecycleProvider {
 *     public Collection&lt;Lifecycle&gt; provides() {
 *         return Collections.singleton(
 *             lifecycle("deploy-docker", Arrays.asList(

 * <p>
 * Example usage:
 * <pre>
 * public class CustomPathScopeProvider implements PathScopeProvider {
 *     public Collection&lt;PathScope&gt; provides() {
 *         return Collections.singleton(pathScope("integration-test",
 *                 ProjectScope.TEST, DependencyScope.TEST));
 *     }
 * }
 * </pre>
 *
 * @see org.apache.maven.api.PathScope

 * <p>
 * Example usage:
 * <pre>
 * public class CustomTypeProvider implements TypeProvider {
 *     public Collection&lt;Type&gt; provides() {
 *         return Arrays.asList(
 *             type("kotlin-library", "jar", "kotlin"),
 *             type("docker-image", "tar.gz", null)
 *         );
 *     }
 * }
 * </pre>
 *
 * @see org.apache.maven.api.Type

    assertTrue(iter.hasNext());
    assertTrue(iter.hasNext());
    assertTrue(iter.hasNext());
    assertEquals(1, (int) iter.next());

    assertFalse(iter.hasNext());

    // Make sure computeNext() doesn't get invoked again
    assertFalse(iter.hasNext());

    assertThrows(NoSuchElementException.class, iter::next);
  }

  public void testDefaultBehaviorOfPeek() {
    /*

   * IOException}, {@code RuntimeException} or {@code Error}. Otherwise, it will be rethrown wrapped
   * in a {@code RuntimeException}. <b>Note:</b> Be sure to declare all of the checked exception
   * types your try block can throw when calling an overload of this method so as to avoid losing
   * the original exception type.
   *