if (m == null || m.isEmpty()) {
                    return;
                }

                for (Map.Entry<Object, Object> entry : m.entrySet()) {
                    Object value = entry.getValue();

                    if (value == null) {
                        continue;
                    }

            Currency.FRANC, Country.SWITZERLAND);
    EnumBiMap<Currency, Country> bimap = EnumBiMap.create(map);
    Set<Object> uniqueEntries = Sets.newIdentityHashSet();
    uniqueEntries.addAll(bimap.entrySet());
    assertEquals(3, uniqueEntries.size());
  }

  @GwtIncompatible
  @J2ktIncompatible
    public void testSerializable() {
    SerializableTester.reserializeAndAssert(

            }
        }

        if (infoMap != null) {
            final List<CrawlingInfoParam> crawlingInfoParamList = new ArrayList<>();
            for (final Map.Entry<String, String> entry : infoMap.entrySet()) {
                final CrawlingInfoParam crawlingInfoParam = new CrawlingInfoParam();
                crawlingInfoParam.setCrawlingInfoId(crawlingInfo.getId());
                crawlingInfoParam.setKey(entry.getKey());

        final Map<String, Object> newDataMap = new LinkedHashMap<>();
        for (final Map.Entry<String, Object> e : dataMap.entrySet()) {
            if (fieldConfigs.getConfig(e.getKey()).map(FieldConfigs.Config::isOverwrite).orElse(false)
                    && e.getValue() instanceof final Object[] values && values.length > 0) {

            RenderDataUtil.register(data, "path", path);
            RenderDataUtil.register(data, "name", name);
            final Map<String, String> tags = new HashMap<>();
            getObjectTags(getObjectName(path, name)).entrySet().forEach(e -> {
                final int index = tags.size() / 2 + 1;
                tags.put("name" + index, e.getKey());
                tags.put("value" + index, e.getValue());
            });

        // Find registrations that match this notification
        for (Map.Entry<String, WitnessRegistration> entry : registrations.entrySet()) {
            WitnessRegistration registration = entry.getValue();

            if (shouldDeliverNotification(registration, notification)) {

        (multiset1, multiset2) -> {
          multiset1.addAll(multiset2);
          return multiset1;
        },
        (Multiset<E> multiset) -> ImmutableMultiset.copyFromEntries(multiset.entrySet()));
  }

  static <T extends @Nullable Object, E extends @Nullable Object, M extends Multiset<E>>
      Collector<T, ?, M> toMultiset(
          Function<? super T, E> elementFunction,

            final StringBuilder queryBuf = new StringBuilder(100);
            final StringBuilder formBuf = new StringBuilder(100);
            for (final Map.Entry<String, String> entry : paramMap.entrySet()) {
                queryBuf.append('&');
                queryBuf.append(URLUtil.encode(entry.getValue(), Constants.UTF_8));
                queryBuf.append('=');

        final Document document = parser.getDocument();

        final StringBuilder buf = new StringBuilder(1000);
        buf.append(getResultDataHeader());
        for (final Map.Entry<String, String> entry : fieldRuleMap.entrySet()) {
            final String path = entry.getValue();
            try {
                final XPathEvaluationResult<?> xObj = getXPathAPI().eval(document, path);
                switch (xObj.type()) {

    Map<@Nullable String, @Nullable String> mapWithNulls = new LinkedHashMap<>();
    mapWithNulls.put("a", null);
    mapWithNulls.put(null, "b");
    Set<Entry<String, String>> entriesWithNulls = mapWithNulls.entrySet();

    assertThrows(NullPointerException.class, () -> j.join(entriesWithNulls));

    assertThrows(NullPointerException.class, () -> j.join(entriesWithNulls.iterator()));