protected Map<Class<? extends B>, B> delegate() {
    return delegate;
  }

  @Override
  @SuppressWarnings("unchecked") // value could not get in if not a T
  @CheckForNull
  public <T extends B> T getInstance(Class<T> type) {
    return (T) delegate.get(checkNotNull(type));
  }

  /**
   * Guaranteed to throw an exception and leave the map unmodified.
   *
   * @throws UnsupportedOperationException always

        TimeoutTask accessTimeoutTask = null;
        if (accessTimeout != null) {
            accessTimeoutTarget = new AccessTimeoutTarget(Thread.currentThread());
            accessTimeoutTask = TimeoutManager.getInstance().addTimeoutTarget(accessTimeoutTarget, accessTimeout, false);
        }

        final ExtractData data = new ExtractData();
        final HttpPost httpPost = new HttpPost(url);

    //                                                                             =======
    @Override
    public AccessTokenDbm asDBMeta() {
        return AccessTokenDbm.getInstance();
    }

    @Override
    public String asTableDbName() {
        return "access_token";
    }

    // ===================================================================================

    private static final UserInfoDbm _instance = new UserInfoDbm();

    private UserInfoDbm() {
    }

    public static UserInfoDbm getInstance() {
        return _instance;
    }

    // ===================================================================================
    //                                                                       Current DBDef

    //                                                                             =======
    @Override
    public SearchLogDbm asDBMeta() {
        return SearchLogDbm.getInstance();
    }

    @Override
    public String asTableDbName() {
        return "search_log";
    }

    @Override
    public boolean hasSpecifiedColumn() {
        return _specification != null;
    }

  }

  @Override
  public String toString() {
    return toString;
  }

  private static MessageDigest getMessageDigest(String algorithmName) {
    try {
      return MessageDigest.getInstance(algorithmName);
    } catch (NoSuchAlgorithmException e) {
      throw new AssertionError(e);
    }
  }

  @Override
  public Hasher newHasher() {
    if (supportsClone) {
      try {

    private static final CrawlingInfoDbm _instance = new CrawlingInfoDbm();

    private CrawlingInfoDbm() {
    }

    public static CrawlingInfoDbm getInstance() {
        return _instance;
    }

    // ===================================================================================
    //                                                                       Current DBDef

    }

    @Override
    public String asEsSearchType() {
        return "file_config";
    }

    @Override
    public FileConfigDbm asDBMeta() {
        return FileConfigDbm.getInstance();
    }

    @Override
    protected <RESULT extends FileConfig> RESULT createEntity(Map<String, Object> source, Class<? extends RESULT> entityType) {
        try {

        TimeoutTask accessTimeoutTask = null;
        if (accessTimeout != null) {
            accessTimeoutTarget = new AccessTimeoutTarget(Thread.currentThread());
            accessTimeoutTask = TimeoutManager.getInstance().addTimeoutTarget(accessTimeoutTarget, accessTimeout, false);
        }

        try {
            return getResponseData(uri, includeContent);
        } finally {
            if (accessTimeoutTarget != null) {

                NtlmFlags.NTLMSSP_NEGOTIATE_ALWAYS_SIGN |
                NtlmFlags.NTLMSSP_NEGOTIATE_KEY_EXCH;
        }
        this.workstation = Type1Message.getDefaultWorkstation();
        log = LogStream.getInstance();
    }

    public String toString() {
        String ret = "NtlmContext[auth=" + auth +
            ",ntlmsspFlags=0x" + Hexdump.toHexString(ntlmsspFlags, 8) +
            ",workstation=" + workstation +