}

    /**
     * Test Rule with null ResponseData
     */
    public void test_matchWithNullResponseData() {
        ConfigurableRule rule = new ConfigurableRule();
        rule.setRuleId("nullTest");
        rule.setResponseProcessor(new TestResponseProcessor("nullProcessor"));

        // Should handle null gracefully
        assertFalse(rule.match(null));
    }

    /**

   * nullText} for any provided null elements.
   */
  public Joiner useForNull(String nullText) {
    checkNotNull(nullText);
    return new Joiner(this) {
      @Override
      CharSequence toString(@Nullable Object part) {
        return (part == null) ? nullText : Joiner.this.toString(part);
      }

      @Override

   * nullText} for any provided null elements.
   */
  public Joiner useForNull(String nullText) {
    checkNotNull(nullText);
    return new Joiner(this) {
      @Override
      CharSequence toString(@Nullable Object part) {
        return (part == null) ? nullText : Joiner.this.toString(part);
      }

      @Override

            if (builder == null) {
                throw new IOException("Builder is null");
            }
            builder.startObject();
            builder.field("null_test", "value");
            builder.endObject();
            return builder;
        };

        // This should handle any IOException gracefully

   *
   * @throws NullPointerException if the first element is null; if this is a possibility, use {@code
   *     iterator().next()} or {@link Iterables#getFirst} instead.
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final Optional<@NonNull E> first() {
    Iterator<E> iterator = getDelegate().iterator();
    return iterator.hasNext() ? Optional.of(iterator.next()) : Optional.absent();

   *
   * @throws NullPointerException if the first element is null; if this is a possibility, use {@code
   *     iterator().next()} or {@link Iterables#getFirst} instead.
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final Optional<@NonNull E> first() {
    Iterator<E> iterator = getDelegate().iterator();
    return iterator.hasNext() ? Optional.of(iterator.next()) : Optional.absent();

  }

  public void testCallableStartsAfterFirstFutureCompletes() {
    @SuppressWarnings({"unused", "nullness"})
    Future<?> possiblyIgnoredError = serializer.submitAsync(firstCallable, directExecutor());
    TestCallable secondCallable = new TestCallable(Futures.<Void>immediateFuture(null));
    @SuppressWarnings({"unused", "nullness"})
    Future<?> possiblyIgnoredError1 = serializer.submitAsync(secondCallable, directExecutor());

        assertNotNull(analyzer);
    }

    @Test
    public void testGetAsList() {
        // Test with null
        List<String> nullList = SuggestUtil.getAsList(null);
        assertNotNull(nullList);
        assertEquals(0, nullList.size());

        // Test with String
        List<String> stringList = SuggestUtil.getAsList("test");
        assertNotNull(stringList);

                }),
        (accum, t) -> {
          /*
           * We assign these to variables before calling checkNotNull to work around a bug in our
           * nullness checker.
           */
          K key = keyFunction.apply(t);
          V newValue = valueFunction.apply(t);
          accum.put(
              checkNotNull(key, "Null key for input %s", t),

                }),
        (accum, t) -> {
          /*
           * We assign these to variables before calling checkNotNull to work around a bug in our
           * nullness checker.
           */
          K key = keyFunction.apply(t);
          V newValue = valueFunction.apply(t);
          accum.put(
              checkNotNull(key, "Null key for input %s", t),