element = mergePlugin(existing, element, sourceDominant, context);
                    } else {
                        added.put(key, element);
                    }
                    merged.put(key, element);
                }

                if (!added.isEmpty()) {
                    PluginManagement pluginMgmt = (PluginManagement) context.get(PLUGIN_MANAGEMENT);

                addToClasspath = false;
            }
            /*
             * If the test output directory provides some modules of its own, add them.
             * Except for this unusual case, tests should never be added to the module-path.
             */
            for (Map.Entry<Path, String> entry : testModules.getModuleNames().entrySet()) {
                if (!outputModules.containsModule(entry.getValue())) {

     * @throws IllegalArgumentException if duplicate key pairs were added
     */
    public ImmutableTable<R, C, V> build() {
      return buildOrThrow();
    }

    /**
     * Returns a newly-created immutable table, or throws an exception if duplicate key pairs were
     * added.
     *
     * @throws IllegalArgumentException if duplicate key pairs were added
     * @since 31.0
     */

   * <p>The collections returned by {@link Multimap#keySet()}, {@link Multimap#keys()}, and {@link
   * Multimap#asMap()} will iterate through the keys in the order that they were first added to the
   * multimap, save that if all values associated with a key are removed and then the key is added
   * back into the multimap, that key will come last in the key iteration order.
   */
  public static MultimapBuilderWithKeys<@Nullable Object> linkedHashKeys() {

    private final ExecutionList executionList = new ExecutionList();

    // This allows us to only start up a thread waiting on the delegate future when the first
    // listener is added.
    private final AtomicBoolean hasListeners = new AtomicBoolean(false);

    // The delegate future.
    private final Future<V> delegate;

    ListenableFutureAdapter(Future<V> delegate) {

  }

  /**
   * A special purpose queue/executor that dispatches listener events serially on a configured
   * executor. Each event can be added and dispatched as separate phases.
   *
   * <p>This class is very similar to {@link SequentialExecutor} with the exception that events can
   * be added without necessarily executing immediately.
   */
  private static final class PerListenerQueue<L> implements Runnable {
    final L listener;

  }

  public void testExceptionThrown_whileClosingLastCloseable() throws IOException {
    Closer closer = new Closer(suppressor);

    IOException exception = new IOException();

    // c1 is added first, closed last
    TestCloseable c1 = closer.register(TestCloseable.throwsOnClose(exception));
    TestCloseable c2 = closer.register(TestCloseable.normal());

    try {
      closer.close();

        return map.containsKey(o);
    }

    /**
     * Adds the specified element to this set if it is not already present.
     *
     * @param o
     *            element to be added to this set.
     * @return true if the set did not already contain the specified
     *         element.
     */
    @Override
    public boolean add(final E o) {
        return map.put(o, PRESENT) == null;
    }

  }

  /** A list that mutates itself after every call to each of its {@link List} methods. */
  interface ConcurrentlyMutatedList<E> extends List<E> {
    /**
     * The elements of a {@link ConcurrentlyMutatedList} are added and removed over time. This
     * method returns every state that the list has passed through at some point.
     */
    Set<List<E>> getAllStates();
  }

  /**

  // here to provide error messages.
  // TODO(user): Some Strings used in the subclasses can be added as static Strings
  // here too.
  static final String ERROR_MODIFIABLE_SET = "Set returned is unexpectedly modifiable";
  static final String ERROR_SELF_LOOP = "self-loops are not allowed";
  static final String ERROR_ADDED_SELF_LOOP = "Should not be allowed to add a self-loop edge.";