new TestStringMapGenerator() {
              @Override
              protected Map<String, String> create(Entry<String, String>[] entries) {
                return unmodifiableMap(toHashMap(entries));
              }
            })
        .named("unmodifiableMap/HashMap")
        .withFeatures(
            MapFeature.ALLOWS_NULL_KEYS,
            MapFeature.ALLOWS_NULL_VALUES,
            MapFeature.ALLOWS_ANY_NULL_QUERIES,

    @Nonnull
    @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

            new TestStringMapGenerator() {
              @Override
              protected Map<String, String> create(Entry<String, String>[] entries) {
                return unmodifiableMap(toHashMap(entries));
              }
            })
        .named("unmodifiableMap/HashMap")
        .withFeatures(
            MapFeature.ALLOWS_NULL_KEYS,
            MapFeature.ALLOWS_NULL_VALUES,
            MapFeature.ALLOWS_ANY_NULL_QUERIES,

      return Collections.unmodifiableMap(super.column(columnKey));
    }

    @Override
    public Set<C> columnKeySet() {
      return Collections.unmodifiableSet(super.columnKeySet());
    }

    @Override
    public Map<C, Map<R, V>> columnMap() {
      Function<Map<R, V>, Map<R, V>> wrapper = unmodifiableWrapper();
      return Collections.unmodifiableMap(Maps.transformValues(super.columnMap(), wrapper));

        this.artifacts = Collections.unmodifiableSet(new HashSet<>(exportedArtifacts));
        this.packages = exportedPackages.stream()
                .collect(collectingAndThen(toMap(identity(), v -> realm), Collections::unmodifiableMap));
    }

    /**
     * Returns artifacts exported by Maven core and core extensions. Artifacts are identified by their
     * groupId:artifactId string key.
     */

        properties.put(
                MavenArtifactProperties.CONSTITUTES_BUILD_PATH,
                String.valueOf(this.pathTypes.contains(JavaPathType.CLASSES)));
        this.properties = Collections.unmodifiableMap(properties);
    }

    @Override
    public String id() {
        return id;
    }

    @Override
    public String getId() {
        return id();
    }

    @Override

        return list != null ? Collections.unmodifiableList(list) : Collections.emptyList();
    }

    private static Map<String, String> unmodifiable(Map<String, String> map) {
        return map != null ? Collections.unmodifiableMap(map) : Collections.emptyMap();
    }

    private static Map<String, String> toMap(Properties properties) {
        if (properties != null && !properties.isEmpty()) {
            return properties.entrySet().stream()

                        delegate.getMojoDescriptor().getPluginDescriptor().getDependencyNode();
                DefaultNode node = new DefaultNode(session, resolverNode, false);
                return Collections.unmodifiableMap(node.stream()
                        .filter(Objects::nonNull)
                        .map(Node::getDependency)
                        .filter(Objects::nonNull)

        Map<K, V> onlyOnRight,
        Map<K, V> onBoth,
        Map<K, ValueDifference<V>> differences) {
      this.onlyOnLeft = unmodifiableMap(onlyOnLeft);
      this.onlyOnRight = unmodifiableMap(onlyOnRight);
      this.onBoth = unmodifiableMap(onBoth);
      this.differences = unmodifiableMap(differences);
    }

    @Override
    public boolean areEqual() {

        Map<K, V> onlyOnRight,
        Map<K, V> onBoth,
        Map<K, ValueDifference<V>> differences) {
      this.onlyOnLeft = unmodifiableMap(onlyOnLeft);
      this.onlyOnRight = unmodifiableMap(onlyOnRight);
      this.onBoth = unmodifiableMap(onBoth);
      this.differences = unmodifiableMap(differences);
    }

    @Override
    public boolean areEqual() {