### Suggester (Main Entry Point)
Location: `src/main/java/org/codelibs/fess/suggest/Suggester.java`

Main operations: `suggest()`, `popularWords()`, `indexer()`, `createIndexIfNothing()`, `createNextIndex()`, `switchIndex()`, `removeDisableIndices()`

### SuggestIndexer (Indexing Engine)
Location: `src/main/java/org/codelibs/fess/suggest/index/SuggestIndexer.java`

Handles all indexing operations, content parsing, and word management (bad words, elevate words).

import org.opensearch.action.admin.indices.get.GetIndexResponse;

/**
 * Tests for Suggester index lifecycle operations including edge cases.
 * Covers: createIndexIfNothing, createNextIndex, switchIndex, removeDisableIndices
 */
public class SuggesterIndexLifecycleTest {
    static OpenSearchRunner runner;

    @Rule
    public final TestName testName = new TestName();

    @BeforeClass

 *   <li>{@link #createNextIndex()}: Creates a new index and replaces the current update alias with the new index.</li>
 *   <li>{@link #switchIndex()}: Switches the search alias to the current update index.</li>
 *   <li>{@link #removeDisableIndices()}: Removes disabled indices.</li>
 *   <li>{@link #indexer()}: Creates a new SuggestIndexer for indexing suggestions.</li>
 *   <li>{@link #builder()}: Creates a new SuggesterBuilder for building Suggester instances.</li>

            if (index.startsWith(suggester.getIndex())) {
                count++;
            }
        }
        assertEquals(2, count);

        suggester.removeDisableIndices();
        response = suggester.suggest().setSuggestDetail(true).execute().getResponse();
        assertEquals(3, response.getNum());