* @return a new, empty hash set with enough capacity to hold {@code expectedSize} elements
   *     without resizing
   * @throws IllegalArgumentException if {@code expectedSize} is negative
   */
  public static <E extends @Nullable Object> HashSet<E> newHashSetWithExpectedSize(
      int expectedSize) {
    return new HashSet<>(Maps.capacity(expectedSize));
  }

  /**

        this.delegate = new ArtifactDescriptorReaderDelegate();
    }

    @Override
    public ArtifactDescriptorResult readArtifactDescriptor(
            RepositorySystemSession session, ArtifactDescriptorRequest request) throws ArtifactDescriptorException {
        ArtifactDescriptorResult result = new ArtifactDescriptorResult(request);

    @Override
    public Map<String, String> getUserProperties() {
        return Collections.unmodifiableMap(new PropertiesAsMap(getMavenSession().getUserProperties()));
    }

    @Nonnull
    @Override
    public Map<String, String> getSystemProperties() {
        return Collections.unmodifiableMap(new PropertiesAsMap(getMavenSession().getSystemProperties()));
    }

    @Nonnull
    @Override

        initializeCleanupMonitoring();
    }

    private void initializeCleanupMonitoring() {
        callerInfo = new NullPointerException().getStackTrace()[2];

        Runnable warning = this::maybeWarnAboutCleanUp;

        cleanupWarning = new Thread(warning);

        Runtime.getRuntime().addShutdownHook(cleanupWarning);
    }

    private void maybeWarnAboutCleanUp() {

        DefaultRepositorySystemSession repoSession = new DefaultRepositorySystemSession(h -> false);
        DefaultMavenExecutionRequest request = new DefaultMavenExecutionRequest();
        MavenSession mavenSession = new MavenSession(repoSession, request, new DefaultMavenExecutionResult());
        DefaultSession session = new DefaultSession(mavenSession, null, null, repositorySystem, null, null);

        return new WrappedNavigableSet(key, (NavigableSet<V>) collection, null);
      } else if (collection instanceof SortedSet) {
        return new WrappedSortedSet(key, (SortedSet<V>) collection, null);
      } else if (collection instanceof Set) {
        return new WrappedSet(key, (Set<V>) collection);
      } else {
        return new WrappedCollection(key, collection, null);
      }
    }

    return (Collector) TO_OPTIONAL;
  }

  private static final Object NULL_PLACEHOLDER = new Object();

  private static final Collector<@Nullable Object, ?, @Nullable Object> ONLY_ELEMENT =
      Collector.<@Nullable Object, ToOptionalState, @Nullable Object>of(
          ToOptionalState::new,
          (state, o) -> state.add((o == null) ? NULL_PLACEHOLDER : o),
          ToOptionalState::combine,

        rsession.setRepositoryListener(Mockito.mock(RepositoryListener.class));

        DefaultMavenExecutionRequest request = new DefaultMavenExecutionRequest();
        MavenSession mavenSession = new MavenSession(rsession, request, new DefaultMavenExecutionResult());
        DefaultSession session = new DefaultSession(mavenSession, null, null, null, null, null);
        InternalSession.associate(rsession, session);

        return rsession;

        AtomicReference<org.apache.maven.api.model.Dependency> modified = new AtomicReference<>();
        assertNotNull(this.newModelResolver().resolveModel(session, dependency, modified));
        assertEquals("1", modified.get().getVersion());
    }

    private ModelResolver newModelResolver() throws Exception {
        return new DefaultModelResolver();
    }

    assertTrue(Arrays.equals(new String[0], array));
  }

  @GwtIncompatible // Iterators.toArray(Iterator, Class)
  public void testToArraySingleton() {
    Iterator<String> iterator = Collections.singletonList("a").iterator();
    String[] array = Iterators.toArray(iterator, String.class);
    assertTrue(Arrays.equals(new String[] {"a"}, array));
  }