public void testPutDuplicateValue() {
    List<Entry<K, V>> entries = copyToList(multimap().entries());

    for (Entry<K, V> entry : entries) {
      resetContainer();

      K k = entry.getKey();
      V v = entry.getValue();

      List<V> values = multimap().get(k);
      List<V> expectedValues = copyToList(values);

      assertTrue(multimap().put(k, v));
      expectedValues.add(v);

                System.getProperties().entrySet().stream().forEach(e -> logger.debug("Property: {}={}", e.getKey(), e.getValue()));
                System.getenv().entrySet().forEach(e -> logger.debug("Env: {}={}", e.getKey(), e.getValue()));
                logger.debug("Option: {}", options);
            } catch (final Exception e) {
                // ignore
            }

  private static final Predicate<@Nullable Integer> EVEN = input -> input == null || input % 2 == 0;
  static final Predicate<Entry<String, Integer>> CORRECT_LENGTH =
      input -> input.getKey().length() == input.getValue();

  abstract Map<String, Integer> createUnfiltered();

  public void testFilteredKeysIllegalPut() {
    Map<String, Integer> unfiltered = createUnfiltered();

  @Override
  protected void assertMoreInvariants(Map<K, V> map) {
    // TODO: can these be moved to MapInterfaceTest?
    for (Entry<K, V> entry : map.entrySet()) {
      assertEquals(entry.getKey() + "=" + entry.getValue(), entry.toString());
    }

    assertEquals("{" + JOINER.join(map.entrySet()) + "}", map.toString());
    assertEquals("[" + JOINER.join(map.entrySet()) + "]", map.entrySet().toString());

            final String hotThreads = response.getNodesMap().entrySet().stream().map(e -> {
                final StringBuilder tempBuf = new StringBuilder();
                append(tempBuf, StringEscapeUtils.escapeJson(e.getKey()), () -> StringEscapeUtils.escapeJson(e.getValue().getHotThreads()));
                return tempBuf.toString();
            }).collect(Collectors.joining(","));
            buf.append(hotThreads).append(',');

  @Override
  protected final void assertMoreInvariants(Map<K, V> map) {
    // TODO: can these be moved to MapInterfaceTest?
    for (Entry<K, V> entry : map.entrySet()) {
      assertEquals(entry.getKey() + "=" + entry.getValue(), entry.toString());
    }

    assertEquals("{" + JOINER.join(map.entrySet()) + "}", map.toString());
    assertEquals("[" + JOINER.join(map.entrySet()) + "]", map.entrySet().toString());

        return LIST_ENDPOINT_SUFFIX;
    }

    @Override
    protected String getItemEndpointSuffix() {
        return ITEM_ENDPOINT_SUFFIX;
    }

    @Override
    protected String getIdKey() {
        return "doc_id";
    }

    @Override
    protected Map<String, Object> createTestParam(int id) {
        final Map<String, Object> requestBody = new HashMap<>();

    for (RemovalNotification<String, String> notification : listener) {
      removalNotifications.put(notification.getKey(), notification.getValue());
      assertEquals(
          "Unexpected key/value pair passed to removalListener",
          notification.getKey(),
          notification.getValue());
    }

    // All of the seed values should have been visible, so we should have gotten removal

    for (RemovalNotification<String, String> notification : listener) {
      removalNotifications.put(notification.getKey(), notification.getValue());
      assertEquals(
          "Unexpected key/value pair passed to removalListener",
          notification.getKey(),
          notification.getValue());
    }

    // All of the seed values should have been visible, so we should have gotten removal

  }

  private String expectedToString(Set<Entry<K, V>> entries) {
    Map<K, V> reference = new LinkedHashMap<>();
    for (Entry<K, V> entry : entries) {
      reference.put(entry.getKey(), entry.getValue());
    }
    return reference.toString();
  }