@Override
    public boolean hasNext() {
      if (modCount != expectedModCount) {
        throw new ConcurrentModificationException();
      }
      return next != null && remaining > 0;
    }

    @Override
    public T next() {
      if (!hasNext()) {
        throw new NoSuchElementException();
      }

      // requireNonNull is safe because of the hasNext check.

            return new Metadata(new MetadataStaxReader().read(in, false));
        } catch (FileNotFoundException e) {
            throw new RepositoryMetadataReadException("Cannot read metadata from '" + mappingFile + "'", e);
        } catch (IOException | XMLStreamException e) {
            throw new RepositoryMetadataReadException(
                    "Cannot read metadata from '" + mappingFile + "': " + e.getMessage(), e);
        }

                if ((ch & 0xC0) != 0x80 ) {
                    throw new IOException( "Invalid UTF-8 sequence" );
                } else {
                    uni[ui] |= (ch & 0x3F) << 6;
                    ch = src[si++] & 0xFF;
                    uni[ui] |=  ch & 0x3F;
                    if ((ch & 0xC0) != 0x80 || uni[ui] < 0x800) {
                        throw new IOException( "Invalid UTF-8 sequence" );
                    }

      override fun fromDer(reader: DerReader): Pair<DerAdapter<*>, Any?> {
        val peekedHeader =
          reader.peekHeader()
            ?: throw ProtocolException("expected a value at $reader")

        val choice =
          choices.firstOrNull { it.matches(peekedHeader) }
            ?: throw ProtocolException(
              "expected a matching choice but was $peekedHeader at $reader",
            )

    resetMap(createArrayWithNullValue());
  }

  /**
   * Equivalent to {@link #expectMissingKeys(Object[]) expectMissingKeys} {@code (null)} except that
   * the call to {@code contains(null)} is permitted to throw a {@code NullPointerException}.
   *
   * @param message message to use upon assertion failure
   */
  protected void expectNullKeyMissingWhenNullKeysUnsupported(String message) {
    try {

        if (StringUtil.isBlank(crawlingInfoId)) {
            throw new CrawlingAccessException("sessionId is null.");
        }

        final CrawlerClientFactory crawlerClientFactory = crawlingConfig.initializeClientFactory(ComponentUtil::getCrawlerClientFactory);
        final CrawlerClient client = crawlerClientFactory.getClient(url);
        if (client == null) {
            throw new CrawlingAccessException("CrawlerClient is null for " + url);

    private boolean startUpCalled = false;

    @Override
    protected void startUp() {
      startUpCalled = true;
      throw new UnsupportedOperationException("kaboom!");
    }

    @Override
    protected void run() {
      throw new AssertionError("run() should not be called");
    }

    @Override
    protected Executor executor() {
      return exceptionCatchingExecutor;

        try {
            final ActionResponse actionResponse = ssoManager.getResponse(SsoResponseType.METADATA);
            if (actionResponse == null) {
                throw responseManager.new400("Unsupported request type.");
            }
            return actionResponse;
        } catch (final SsoMessageException e) {
            if (e.getCause() == null) {

      "u" -> username = value
      "pass" -> password = value
      "h" -> host = value
      "port" -> port = value
      "p" -> path = value
      "q" -> query = value
      "f" -> fragment = value
      else -> throw IllegalArgumentException("unexpected attribute: $value")
    }
  }

  override fun toString(): String = format("Parsing: <%s> against <%s>", input!!, base!!)

  companion object {

      // permitted not to throw because it would be a no-op
    }
    expectUnchanged();
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_KEY_QUERIES)
  public void testReplace_absentNullKeyUnsupported() {
    try {
      getMap().replace(null, v3());
    } catch (NullPointerException tolerated) {
      // permitted not to throw because it would be a no-op
    }
    expectUnchanged();