* java.util.stream.Stream#filter}. This method is not being deprecated, but we gently encourage
   * you to migrate to streams.
   */
  // TODO(kevinb): how to omit that last sentence when building GWT javadoc?
  public static <E extends @Nullable Object> Set<E> filter(
      Set<E> unfiltered, Predicate<? super E> predicate) {
    if (unfiltered instanceof SortedSet) {
      return filter((SortedSet<E>) unfiltered, predicate);

                .getOrDefault(artifact.getGroupId(), Collections.emptyMap())
                .getOrDefault(artifact.getArtifactId(), Collections.emptyMap())
                .values()
                .stream()
                .filter(p -> Objects.nonNull(findArtifact(p, artifact)))
                .map(MavenProject::getVersion)
                .collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));
    }

        }
        return parent;
    }

    private Map<String, Activation> getProfileActivations(Model model) {
        return model.getProfiles().stream()
                .filter(p -> p.getActivation() != null)
                .collect(Collectors.toMap(Profile::getId, Profile::getActivation));
    }

    private Model injectProfileActivations(Model model, Map<String, Activation> activations) {

            Map<?, ?> map = (Map) session.getCache().get(session, DefaultModelCache.class.getName());
            List<String> paths = map.keySet().stream()
                    .map(Object::toString)
                    .filter(s -> s.startsWith("SourceCacheKey"))
                    .map(s -> s.substring("SourceCacheKey[location=".length(), s.indexOf(", tag")))
                    .sorted()
                    .distinct()

            // which may cause some re-entrance in the build() method and can
            // actually cause deadlocks.  In order to workaround the problem,
            // we do a first pass by reading all rawModels in order.
            List<ProjectBuildingResult> results = new ArrayList<>();
            boolean failure = false;
            for (InterimResult r : interimResults) {

    }

    private static final long serialVersionUID = 5;
  }

  public void testMutableValues() {
    IntHolder holderA = new IntHolder(1);
    IntHolder holderB = new IntHolder(2);
    Map<String, IntHolder> map = ImmutableMap.of("a", holderA, "b", holderB);
    holderA.value = 3;
    assertTrue(map.entrySet().contains(Maps.immutableEntry("a", new IntHolder(3))));

    }

    protected DefaultModelRepositoryHolder(DefaultModelRepositoryHolder holder) {
        this.session = holder.session;
        this.repositoryMerging = holder.repositoryMerging;
        this.pomRepositories = List.copyOf(holder.pomRepositories);
        this.externalRepositories = List.copyOf(holder.externalRepositories);
        this.repositories = List.copyOf(holder.repositories);
    }

    @Override

     *
     * @param session The session to use to resolve the model, must not be {@code null}.
     * @param parent The parent coordinates to resolve, must not be {@code null}.
     * @param modified a holder for the updated parent, must not be {@code null}.
     * @return The source of the requested POM, never {@code null}.
     * @throws ModelResolverException If the POM could not be resolved from any configured repository.
     */

   * underlying multimap.
   *
   * <p>The returned multimap isn't threadsafe or serializable, even if {@code unfiltered} is.
   *
   * <p>Many of the filtered multimap's methods, such as {@code size()}, iterate across every
   * key/value mapping in the underlying multimap and determine which satisfy the filter. When a

        if (session.getMavenSession().getAllProjects() != null) {
            session.getMavenSession().getAllProjects().stream()
                    .flatMap(this::getProjectArtifacts)
                    .filter(a -> Objects.equals(id, id(a)))
                    .forEach(a -> a.setFile(path != null ? path.toFile() : null));
        }
        if (path == null) {
            paths.remove(id);
        } else {