public ImmutableBiMap<K, V> build() {
      return buildOrThrow();
    }

    @Override
    public ImmutableBiMap<K, V> buildOrThrow() {
      ImmutableMap<K, V> map = super.buildOrThrow();
      if (map.isEmpty()) {
        return of();
      }
      return new RegularImmutableBiMap<K, V>(super.buildOrThrow());
    }

    @Override
    ImmutableBiMap<K, V> buildJdkBacked() {
      return build();
    }

    @Override
    public Artifact createPluginArtifact(Plugin plugin) {
        VersionRange versionRange;
        try {
            String version = plugin.getVersion();
            if (version == null || version.isEmpty()) {
                version = "RELEASE";
            }
            versionRange = VersionRange.createFromVersionSpec(version);
        } catch (InvalidVersionSpecificationException e) {
            return null;

    }

    /**
     * @throws Exception
     */
    @Test
    public void testIsEmpty() throws Exception {
        assertThat(list.isEmpty(), is(true));
        list.addLast("1");
        assertThat(list.isEmpty(), is(not(true)));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testContaines() throws Exception {

     * @param urlList The list of URL patterns to include.
     */
    @Override
    public void addIncludeUrlFilter(final String sessionId, final List<String> urlList) {
        if (urlList.isEmpty()) {
            return;
        }
        final List<OpenSearchUrlFilter> urlFilterList = new ArrayList<>(urlList.size());
        for (final String url : urlList) {

        assertEquals(DirectoryCacheScope.IMMEDIATE_CHILDREN, entry.getScope());
        assertFalse(entry.isComplete());
        assertFalse(entry.hasChanges());
        assertTrue(entry.getChildren().isEmpty());
    }

    @Test
    public void testUpdateChild() {
        String childName = "file1.txt";
        long size = 1024L;
        long lastModified = System.currentTimeMillis();

        if (pluginGroups != null) {
            for (int i = 0; i < pluginGroups.size(); i++) {
                String pluginGroup = pluginGroups.get(i).trim();

                if (pluginGroup.isEmpty()) {
                    addViolation(
                            problems, Severity.ERROR, "pluginGroups.pluginGroup[" + i + "]", null, "must not be empty");
                } else if (!ID_REGEX.matcher(pluginGroup).matches()) {

  }

  @Override
  public boolean isEmpty() {
    return false;
  }

  @Override
  @SuppressWarnings("unchecked") // TODO(cpovirk): Use a shared unsafeCompare method.
  public ContiguousSet<C> intersection(ContiguousSet<C> other) {
    checkNotNull(other);
    checkArgument(this.domain.equals(other.domain));
    if (other.isEmpty()) {
      return other;
    } else {

  // original character value.
  @VisibleForTesting
  static char[][] createReplacementArray(Map<Character, String> map) {
    checkNotNull(map); // GWT specific check (do not optimize)
    if (map.isEmpty()) {
      return EMPTY_REPLACEMENT_ARRAY;
    }
    char max = max(map.keySet());
    char[][] replacements = new char[max + 1][];
    for (Character c : map.keySet()) {
      replacements[c] = map.get(c).toCharArray();

                // if we're building an argument, keep doing so.
                // if this is the case of "-Dfoo=bar", then we need to adjust the buffer.
                if (!currentArg.isEmpty()) {
                    currentArg.setLength(currentArg.length() - 1);
                }

                cleaned.add(currentArg.toString());

                currentArg = null;
                continue;

        apilink.setAttribute("style", classDoc.getStyle());
    }

    private void addSubtypeLinks(ClassDoc classDoc, Element parent, Document document) {
        if (!classDoc.getSubClasses().isEmpty()) {
            Element list = document.createElement("segmentedlist");
            parent.appendChild(list);
            Element segtitle = document.createElement("segtitle");
            list.appendChild(segtitle);