* @param model The model to validate, must not be {@code null}.
     * @param request The model building request that holds further settings, must not be {@code null}.
     * @param problems The container used to collect problems that were encountered, must not be {@code null}.
     * @since 4.0.0
     */
    default void validateExternalProfiles(

        final T value = getValue(doc, key, clazz);
        if (value == null) {
            return defaultValue;
        }
        return value;
    }

    @SuppressWarnings("unchecked")
    public static <T> T getValue(final Map<String, Object> doc, final String key, final Class<T> clazz) {
        if (doc == null || key == null) {
            return null;
        }

        final Object value = doc.get(key);

                .findFirst();
    }

    File getBaseDirectoryFromRequest(MavenExecutionRequest request) {
        return request.getBaseDirectory() != null ? new File(request.getBaseDirectory()) : null;
    }

    boolean isMatchingProject(MavenProject project, String selector, File reactorDirectory) {
        // [groupId]:artifactId
        if (selector.contains(":")) {

        new AbstractLoadingCache<Object, Object>() {
          @Override
          public Object get(Object key) throws ExecutionException {
            Object v = valueRef.get();
            if (v == null) {
              throw new ExecutionException(cause);
            }
            return v;
          }

          @Override
          public @Nullable Object getIfPresent(Object key) {

  @Override
  @CheckForNull
  public Entry<K, V> firstEntry() {
    return Iterators.<@Nullable Entry<K, V>>getNext(entryIterator(), null);
  }

  @Override
  @CheckForNull
  public Entry<K, V> lastEntry() {
    return Iterators.<@Nullable Entry<K, V>>getNext(descendingEntryIterator(), null);
  }

  @Override
  @CheckForNull
  public Entry<K, V> pollFirstEntry() {
    return Iterators.pollNext(entryIterator());
  }

        Thread th = new Thread(() -> {
            try {
                Thread.sleep(1000);
            } catch (InterruptedException ignore) {}
            deferred.resolve(new SuggestResponse("", 0, Collections.emptyList(), 0, null));
        });
        th.start();

        final CountDownLatch latch = new CountDownLatch(1);
        deferred.promise().then(response -> latch.countDown());
        assertTrue(latch.await(10, TimeUnit.SECONDS));

        if (classpath == null || classpath.size() < 1) {
            return null;
        }

        MetadataTreeNode tree = null;
        MetadataTreeNode parent = null;

        for (ArtifactMetadata md : classpath) {
            MetadataTreeNode node = new MetadataTreeNode(md, parent, md.isResolved(), md.getArtifactScope());
            if (tree == null) {
                tree = node;
            }

            mavenConf = context.installationDirectory.resolve(context.systemProperties.get(MAVEN_INSTALLATION_CONF));
        } else if (context.systemProperties.get("maven.conf") != null) {
            mavenConf = context.installationDirectory.resolve(context.systemProperties.get("maven.conf"));
        } else if (context.systemProperties.get(MAVEN_HOME) != null) {

            long id = 0;
            String line = null;
            while ((line = reader.readLine()) != null) {
                if (line.length() == 0 || line.charAt(0) == '#') {
                    if (updater != null) {
                        updater.write(line);
                    }
                    continue; // ignore empty lines and comments

        BeanUtil.copyMapToBean(null, new Object());
    }

    /**
     *
     */
    @Test
    public void testCopyBeanToMap_DestNull() {
        exception.expect(NullArgumentException.class);
        exception.expectMessage(is("[ECL0008]argument[dest] is null."));
        BeanUtil.copyBeanToMap(new Object(), null);
    }

    /**
     *
     */