assertThrows(Graph.CycleDetectedException.class, () -> graph.addEdge("a2", "a1"));
    }

    @Test
    public void testPerf() throws IOException {
        List<String[]> data = new ArrayList<>();
        String k = null;
        for (String line : Files.readAllLines(Paths.get("src/test/resources/dag.txt"))) {
            if (line.startsWith("\t")) {
                data.add(new String[] {k, line.trim()});
            } else {

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

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

    }

    @SuppressWarnings("deprecation")
    public static String getSearchEngineHttpAddress() {
        final String value = System.getProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS);
        if (value != null) {
            return value;
        }
        return System.getProperty(Constants.FESS_ES_HTTP_ADDRESS);
    }

    Builder<String, Integer> builder = new Builder<>();
    assertThrows(
        NullPointerException.class, () -> builder.put(immutableEntry("one", (Integer) null)));
    assertThrows(NullPointerException.class, () -> builder.put(immutableEntry((String) null, 1)));
  }

  public void testBuilderWithExpectedKeysNegative() {
    assertThrows(

    return Sets.newHashSetWithExpectedSize(expectedSize);
  }

  static <E> Set<E> newConcurrentHashSet() {
    // GWT's ConcurrentHashMap is a wrapper around HashMap, but it rejects null keys, which matches
    // the behaviour of the non-GWT implementation of newConcurrentHashSet().
    // On the other hand HashSet might be better for code size if apps aren't

    assertEquals("foo%7Cbar", e.escape("foo%7Cbar")); // idempotent
  }

  /** Test that giving a null 'safeChars' string causes a {@link NullPointerException}. */
  public void testBadArguments_null() {
    assertThrows(NullPointerException.class, () -> new PercentEscaper(null, false));
  }

  /**
   * Tests that specifying any alphanumeric characters as 'safe' causes an {@link

  static <T extends Throwable> T assertThrows(
      Class<T> expectedThrowable, ThrowingRunnable runnable) {
    return doAssertThrows(
        expectedThrowable,
        () -> {
          runnable.run();
          return null;
        },
        /* userPassedSupplier= */ false);
  }

  private static <T extends Throwable> T doAssertThrows(
      Class<T> expectedThrowable, ThrowingSupplier supplier, boolean userPassedSupplier) {

  public abstract void clear();

  // Views

  @LazyInit @CheckForNull private transient Set<E> elementSet;

  @Override
  public Set<E> elementSet() {
    Set<E> result = elementSet;
    if (result == null) {
      elementSet = result = createElementSet();
    }
    return result;
  }

  /**
   * Creates a new instance of this multiset's element set, which will be returned by {@link
   * #elementSet()}.

    protected abstract Pattern getTagPattern();

    @Override
    public ExtractData getText(final InputStream in, final Map<String, String> params) {
        if (in == null) {
            throw new CrawlerSystemException("The inputstream is null.");
        }
        try {
            final BufferedInputStream bis = new BufferedInputStream(in);
            final String enc = getEncoding(bis);