// Test setting index name with lowercase conversion
        SuggestSettingsBuilder result = builder.setSettingsIndexName("TEST_INDEX");
        assertEquals(builder, result); // Test method chaining
        assertEquals("test_index", builder.settingsIndexName);

        // Test setting index name with mixed case
        builder.setSettingsIndexName("TeSt_InDeX_NaMe");
        assertEquals("test_index_name", builder.settingsIndexName);

    /**
     * Sets the settings index name.
     * @param settingsIndexName The settings index name.
     * @return This builder instance.
     */
    public SuggestSettingsBuilder setSettingsIndexName(final String settingsIndexName) {
        this.settingsIndexName = settingsIndexName.toLowerCase(Locale.ENGLISH);
        return this;
    }

    /**
     * Adds an initial setting.

            }
        };

        final Normalizer normalizer = (text, field, lang) -> null;

        final Suggester suggester = Suggester.builder()
                .settings(SuggestSettings.builder().setSettingsIndexName(settingsIndexName))
                .readingConverter(converter)
                .normalizer(normalizer)
                .build(runner.client(), id);

        assertEquals(runner.client(), suggester.client);

        settingsBuilder.indicesTimeout(fessConfig.getIndexIndicesTimeout());
        settingsBuilder.searchTimeout(fessConfig.getIndexSearchTimeout());
        settingsBuilder.setSettingsIndexName(fessConfig.getIndexDocumentSuggestIndex() + "_suggest");
        suggester = Suggester.builder().settings(settingsBuilder).build(searchEngineClient, fessConfig.getIndexDocumentSuggestIndex());