* @return the element type if this field is a parameterized {@link Collection}, otherwise {@literal null}
     */
    Class<?> getElementClassOfCollection();

    /**
     * Returns the key type if this field is a parameterized {@link Map}.
     *
     * @return the key type if this field is a parameterized {@link Map}, otherwise {@literal null}
     */
    Class<?> getKeyClassOfMap();

    /**

    assertThrows(
        NullPointerException.class, () -> builder.put(immutableCell((Character) null, 1, "foo")));
    assertThrows(
        NullPointerException.class, () -> builder.put(immutableCell('a', (Integer) null, "foo")));
    assertThrows(
        NullPointerException.class, () -> builder.put(immutableCell('a', 1, (String) null)));
  }

  private static class StringHolder {
    @Nullable String string;
  }

            private static final long serialVersionUID = 1L;

            @Override
            public String getCrawlerDocumentMimetypeExtensionOverrides() {
                return null;
            }
        });

        mimeTypeHelper.init();

        // Null config means no override
        try (InputStream is = new ByteArrayInputStream("Hello world".getBytes(StandardCharsets.UTF_8))) {

    @LazyInit @Nullable LinearTransformation inverse;

    RegularLinearTransformation(double slope, double yIntercept) {
      this.slope = slope;
      this.yIntercept = yIntercept;
      this.inverse = null; // to be lazily initialized
    }

    RegularLinearTransformation(double slope, double yIntercept, LinearTransformation inverse) {
      this.slope = slope;
      this.yIntercept = yIntercept;

                final String filteredValue = propertyFilter.filter(propertyKey, plainValue);
                verifyPropertyValue(propertyKey, filteredValue); // null checked
                return filterPropertyAsDefault(filteredValue); // not null here
            }

            private String getFromCache(final String propertyKey) {
                try {
                    return cache.get(propertyKey, () -> {

    prepTask: String? = null,
    promoteTask: String,
    triggerName: String,
    gitUserName: String = "bot-teamcity",
    gitUserEmail: String = "******@****.***",
    extraParameters: String = "",
) : BasePublishGradleDistribution(promotedBranch, prepTask, triggerName, gitUserName, gitUserEmail, extraParameters) {
    init {
        steps {
            if (prepTask != null) {

        doUpdate(entity, null);
    }

    public void insertOrUpdate(CrawlingInfoParam entity) {
        doInsertOrUpdate(entity, null, null);
    }

    public void insertOrUpdate(CrawlingInfoParam entity, RequestOptionCall<IndexRequestBuilder> opLambda) {
        entity.asDocMeta().indexOption(opLambda);
        doInsertOrUpdate(entity, null, null);
    }

        doUpdate(entity, null);
    }

    public void insertOrUpdate(RoleType entity) {
        doInsertOrUpdate(entity, null, null);
    }

    public void insertOrUpdate(RoleType entity, RequestOptionCall<IndexRequestBuilder> opLambda) {
        entity.asDocMeta().indexOption(opLambda);
        doInsertOrUpdate(entity, null, null);
    }

    public void delete(RoleType entity) {

        doUpdate(entity, null);
    }

    public void insertOrUpdate(UserInfo entity) {
        doInsertOrUpdate(entity, null, null);
    }

    public void insertOrUpdate(UserInfo entity, RequestOptionCall<IndexRequestBuilder> opLambda) {
        entity.asDocMeta().indexOption(opLambda);
        doInsertOrUpdate(entity, null, null);
    }

    public void delete(UserInfo entity) {

                }
            """
        ) {
            assertHasErrors(
                "Method com.example.Source.foo(): From non-null returning to null-unmarked returning breaking change.",
                "Method com.example.Source.baz(): From non-null returning to null-unmarked returning breaking change.",
            )
            assertHasNoWarning()