//                                                                           =========
    private static final RequestHeaderDbm _instance = new RequestHeaderDbm();

    private RequestHeaderDbm() {
    }

    public static RequestHeaderDbm getInstance() {
        return _instance;
    }

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

    //                                                                           =========
    private static final GroupDbm _instance = new GroupDbm();

    private GroupDbm() {
    }

    public static GroupDbm getInstance() {
        return _instance;
    }

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

    //                                                                           =========
    private static final DuplicateHostDbm _instance = new DuplicateHostDbm();

    private DuplicateHostDbm() {
    }

    public static DuplicateHostDbm getInstance() {
        return _instance;
    }

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

    //                                                                           =========
    private static final RelatedQueryDbm _instance = new RelatedQueryDbm();

    private RelatedQueryDbm() {
    }

    public static RelatedQueryDbm getInstance() {
        return _instance;
    }

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

    //                                                                           =========
    private static final RoleTypeDbm _instance = new RoleTypeDbm();

    private RoleTypeDbm() {
    }

    public static RoleTypeDbm getInstance() {
        return _instance;
    }

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

      if (Serializable.class.isAssignableFrom(classToTest)) {
        try {
          Object instance = tester.instantiate(classToTest);
          if (instance != null) {
            if (isEqualsDefined(classToTest)) {
              SerializableTester.reserializeAndAssert(instance);
            } else {
              SerializableTester.reserialize(instance);
            }
          }
        } catch (Throwable e) {

    //                                                                           =========
    private static final RelatedContentDbm _instance = new RelatedContentDbm();

    private RelatedContentDbm() {
    }

    public static RelatedContentDbm getInstance() {
        return _instance;
    }

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

    //                                                                           =========
    private static final CrawlingInfoDbm _instance = new CrawlingInfoDbm();

    private CrawlingInfoDbm() {
    }

    public static CrawlingInfoDbm getInstance() {
        return _instance;
    }

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

    //                                                                           =========
    private static final KeyMatchDbm _instance = new KeyMatchDbm();

    private KeyMatchDbm() {
    }

    public static KeyMatchDbm getInstance() {
        return _instance;
    }

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

  /**
   * Returns the empty multimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting is safe because the multimap will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableListMultimap<K, V> of() {
    return (ImmutableListMultimap<K, V>) EmptyImmutableListMultimap.INSTANCE;
  }

  /** Returns an immutable multimap containing a single entry. */