* comparably to {@link Collections#singletonList}, but will not accept a null element. It is
   * preferable mainly for consistency and maintainability of your code.
   *
   * @throws NullPointerException if the element is null
   */
  public static <E> ImmutableList<E> of(E e1) {
    return new SingletonImmutableList<>(e1);
  }

  /**

        final Map<String, MappingMetadata> indexMappings = getMappingsResponse.mappings();
        final MappingMetadata mappingMetadata = indexMappings != null ? indexMappings.get(index) : null;
        if (mappingMetadata == null || mappingMetadata.sourceAsMap().isEmpty()) {
            final AcknowledgedResponse putMappingResponse = fesenClient.get(c -> {

	})
	assertEqualSQL(t, `INSERT INTO "users" ("created_at","updated_at","deleted_at","name","age","birthday","company_id","manager_id","active") VALUES ('2021-10-18 00:00:00','2021-10-18 00:00:00',NULL,'foo',20,NULL,NULL,NULL,false) RETURNING "id"`, sql)

	// save
	user = &User{Name: "foo", Age: 20}
	user.CreatedAt = date
	user.UpdatedAt = date
	sql = DB.ToSQL(func(tx *gorm.DB) *gorm.DB {

   * {@link Equivalence#equivalent} returns {@code true} if both values are null, or if neither
   * value is null and {@link Object#equals} returns {@code true}. {@link Equivalence#hash} returns
   * {@code 0} if passed a null value.
   *
   * @since 13.0
   * @since 8.0 (in Equivalences with null-friendly behavior)
   * @since 4.0 (in Equivalences)
   */
  public static Equivalence<Object> equals() {

     * @return the selected channel, or null if no channels available
     */
    public ChannelInfo selectChannel(String sessionId) {
        ChannelGroup channelGroup = sessionChannels.get(sessionId);
        if (channelGroup == null) {
            log.warn("No channel group found for session {}", sessionId);
            return null;
        }

                // 0 bytes
                Arguments.of(0L, null, "0 B"),
                Arguments.of(0L, ScaleUnit.BYTE, "0 B"),
                Arguments.of(0L, ScaleUnit.KILOBYTE, "0 kB"),
                Arguments.of(0L, ScaleUnit.MEGABYTE, "0 MB"),
                Arguments.of(0L, ScaleUnit.GIGABYTE, "0 GB"),

                // 5 bytes
                Arguments.of(5L, null, "5 B"),
                Arguments.of(5L, ScaleUnit.BYTE, "5 B"),

                logger.warn("Could not add document: url field is missing or null");
                return;
            }

            final String url = dataMap.get(fessConfig.getIndexFieldUrl()).toString();
            final CrawlerClient client = crawlerClientFactory.getClient(url);
            if (client == null) {

   *
   * @param element the element to add one occurrence of; may be null only if explicitly allowed by
   *     the implementation
   * @return {@code true} always, since this call is required to modify the multiset, unlike other
   *     {@link Collection} types
   * @throws NullPointerException if {@code element} is null and this implementation does not permit
   *     null elements

    @RetainedLocalRef ListenableFuture<? extends I> localInputFuture = inputFuture;
    @RetainedLocalRef F localFunction = function;
    if (isCancelled() | localInputFuture == null | localFunction == null) {
      return;
    }
    inputFuture = null;

    if (localInputFuture.isCancelled()) {
      @SuppressWarnings("unchecked")
      boolean unused =

    void testResolve_NullRoot() throws SmbAuthException {
        // Scenario: The root is null.
        assertNull(dfsImpl.resolve(mockContext, "domain", null, "/path"));
    }

    @Test
    void testResolve_NullDomain() throws SmbAuthException {
        // Scenario: The domain is null.
        assertNull(dfsImpl.resolve(mockContext, null, "root", "/path"));
    }

    // Tests for cache
    @Test