}

    @Test
    public void test_highlightedFields_withNull() {
        queryFieldConfig.highlightedFields = null;

        // When highlightedFields is null, the method should handle it gracefully
        // or throw an exception. Test the actual behavior.
        queryFieldConfig.highlightedFields(stream -> {
            // If it doesn't throw NPE, it should provide an empty stream

                highlightBuilder.preTags(preTags);
            }
            if (postTags != null) {
                highlightBuilder.postTags(postTags);
            }
            queryFieldConfig.highlightedFields(
                    stream -> stream.forEach(hf -> highlightBuilder.field(new HighlightBuilder.Field(hf).highlighterType(highlighterType)
                            .fragmentSize(fragmentSize)