PlexusConfiguration[] ces = c.getChildren();
        if (ces != null) {
            for (PlexusConfiguration ce : ces) {
                String value = ce.getValue(null);
                String defaultValue = ce.getAttribute("default-value", null);
                if (value != null || defaultValue != null) {
                    XmlNode e = XmlNode.newInstance(
                            ce.getName(),

     * @param root the Maven Dependency, must not be {@code null}
     * @param scope the {link PathScope} to collect dependencies, must not be {@code null}
     * @return the collection result, never {@code null}
     * @throws DependencyResolverException if the dependency tree could not be built
     * @throws IllegalArgumentException if an argument is null or invalid

                null, null, null))
        .addEqualityGroup(
            Tables.<String, @Nullable Object, @Nullable Object>immutableCell("bar", null, null))
        .addEqualityGroup(
            Tables.<@Nullable Object, Integer, @Nullable Object>immutableCell(null, 2, null))
        .addEqualityGroup(
            Tables.<@Nullable Object, @Nullable Object, Character>immutableCell(null, null, 'b'))

        DefaultProblemCollector collector = new DefaultProblemCollector(null);

        collector.add(null, "PROBLEM1", -1, -1, null);

        collector.setSource("SOURCE_PROBLEM2");
        collector.add(null, "PROBLEM2", -1, -1, null);

        collector.setSource("SOURCE_PROBLEM3");
        collector.add(null, "PROBLEM3", -1, -1, null);

        assertEquals("", collector.getProblems().get(0).getSource());

            throws GraphConflictResolutionException {
        if (policy == null) {
            throw new GraphConflictResolutionException("no GraphConflictResolutionPolicy injected");
        }

        if (graph == null) {
            return null;
        }

        final MetadataGraphVertex entry = graph.getEntry();
        if (entry == null) {
            return null;
        }

        if (graph.isEmpty()) {

     *
     * @param projectFile The POM file to build the project from, must not be {@code null}.
     * @param request The project building request that holds further parameters, must not be {@code null}.
     * @return The result of the project building, never {@code null}.
     * @throws ProjectBuildingException If the project descriptor could not be successfully built.
     */

      return;
    }

    map.put(null, unmappedValue);
    assertEquals(unmappedValue, map.get(null));
    assertTrue(map.containsKey(null));
    Entry<@Nullable K, V> entry = mapEntry(null, unmappedValue);
    assertTrue(entrySet.remove(entry));
    assertNull(map.get(null));
    assertFalse(map.containsKey(null));
  }

  public void testEntrySetRemoveNullKeyMissing() {

     *
     * @param message The message describing the problem, may be {@code null}.
     * @param severity The severity level of the problem, may be {@code null} to default to
     *            {@link ModelProblem.Severity#ERROR}.
     * @param source The source of the problem, may be {@code null}.
     * @param lineNumber The one-based index of the line containing the error or {@code -1} if unknown.

     */
    @Nonnull
    String getProjectId();

    /**
     * Gets the POM file from which the project was built.
     *
     * @return the optional POM file
     */
    @Nonnull
    Optional<Path> getPomFile();

    /**
     * Gets the project that was built.
     *

                        "name": {
                            "anyOf": [{"type": "string"}, {"type": "null"}],
                            "title": "Name",
                        },
                        "description": {
                            "anyOf": [{"type": "string"}, {"type": "null"}],
                            "title": "Description",
                        },
                        "price": {