* @return this request for chaining, never {@code null}
         */
        @Nonnull
        public DependencyResolverRequestBuilder rootArtifact(@Nullable Artifact rootArtifact) {
            this.rootArtifact = rootArtifact;
            return this;
        }

        /**
         * @param root The root dependency
         * @return this request for chaining, never {@code null}
         */

 *       directly
 *   <li>Pass a <i>pre-existing</i> {@link Comparator} instance to {@link #from(Comparator)}
 *   <li>Use the natural ordering, {@link Ordering#natural}
 * </ul>
 *
 * <h4>Chaining</h4>
 *
 * <p>Then you can use the <i>chaining</i> methods to get an altered version of that {@code
 * Ordering}, including:
 *
 * <ul>
 *   <li>{@link #reverse}
 *   <li>{@link #compound(Comparator)}
 *   <li>{@link #onResultOf(Function)}

    } catch (AssertionFailedError expected) {
      return;
    }
    fail("Should have failed");
  }

  /** An interface for the 2 ways that a chaining call might be defined. */
  private interface ChainingCalls {
    // A method that is defined to 'return this'
    @CanIgnoreReturnValue
    ChainingCalls chainingCall();

 *       directly
 *   <li>Pass a <i>pre-existing</i> {@link Comparator} instance to {@link #from(Comparator)}
 *   <li>Use the natural ordering, {@link Ordering#natural}
 * </ul>
 *
 * <h4>Chaining</h4>
 *
 * <p>Then you can use the <i>chaining</i> methods to get an altered version of that {@code
 * Ordering}, including:
 *
 * <ul>
 *   <li>{@link #reverse}
 *   <li>{@link #compound(Comparator)}
 *   <li>{@link #onResultOf(Function)}

   * perform actual validation of IP addresses, see the {@link InetAddresses#forString(String)}
   * method.
   *
   * @return {@code this}, to enable chaining of calls.
   * @throws IllegalArgumentException if bracketless IPv6 is detected.
   */
  @CanIgnoreReturnValue
  public HostAndPort requireBracketsForIPv6() {

     *            the mid to set
     */
    @Override
    public final void setMid ( long mid ) {
        this.mid = mid;
    }


    /**
     * @param n
     * @return whether chaining was successful
     */
    public boolean chain ( ServerMessageBlock2 n ) {
        if ( this.next != null ) {
            return this.next.chain(n);
        }

 *         .transform(ActivityService::isLoggedIn, threadPool)
 *         .catching(RpcException.class, e -> false, directExecutor());
 * }</pre>
 *
 * <h3>Alternatives</h3>
 *
 * <h4>Frameworks</h4>
 *
 * <p>When chaining together a graph of asynchronous operations, you will often find it easier to
 * use a framework. Frameworks automate the process, often adding features like monitoring,
 * debugging, and cancellation. Examples of frameworks include:

 * >streams library</a> in a slightly different way.
 *
 * <p>The following types of methods are provided:
 *
 * <ul>
 *   <li>chaining methods which return a new {@code FluentIterable} based in some way on the
 *       contents of the current one (for example {@link #transform})

    to the uncaught exception handler for reporting and recovery.

 *  Fix: Un-deprecate `MockResponse.setHeaders()` and other setters. These were deprecated in OkHttp
    4.0 but that broke method chaining for Java callers.

 *  Fix: Don't crash on HTTP/2 HEAD requests when the `Content-Length` header is present but is not
    consistent with the length of the response body.

  public void testIsPresent_yes() {
    assertTrue(Optional.of("training").isPresent());
  }

  public void testGet_absent() {
    Optional<String> optional = Optional.absent();
    assertThrows(IllegalStateException.class, optional::get);
  }

  public void testGet_present() {
    assertEquals("training", Optional.of("training").get());
  }