* first node in insertion order; all values at indices ≥ {@link #size()} are UNSET.
   */
  private transient int @Nullable [] predecessor;

  /**
   * Pointer to the successor of an entry in insertion order. ENDPOINT indicates a node is the last
   * node in insertion order; all values at indices ≥ {@link #size()} are UNSET.
   */
  private transient int @Nullable [] successor;

/**
 * Fess-specific crawler configuration that extends OpenSearchCrawlerConfig.
 * This class provides configuration settings for the Fess crawler including
 * index names, shard counts, and replica counts for queue, data, and filter indices.
 */
public class FessCrawlerConfig extends OpenSearchCrawlerConfig {

    /**
     * Default constructor.
     */
    public FessCrawlerConfig() {
        super();
    }

    /**

└── fess_indices/              # OpenSearch index mappings

src/main/webapp/WEB-INF/view/  # JSP templates
```

## DBFlute Code Generation

DBFlute generates type-safe data access code for OpenSearch indices:

```bash
mvn dbflute:freegen
```

Generated code:
- `opensearch/{index}/bsentity/` - Base entities (do not edit)
- `opensearch/{index}/exentity/` - Extended entities (customize here)

    @AfterClass
    public static void afterClass() throws Exception {
        runner.close();
        runner.clean();
    }

    @Before
    public void before() throws Exception {
        runner.admin().indices().prepareDelete("_all").execute().actionGet();
        runner.refresh();
        settings = Suggester.builder().build(runner.client(), id).settings();
    }

    @Test
    public void test_setAndGetAsArray() {

    @AfterClass
    public static void afterClass() throws Exception {
        runner.close();
        runner.clean();
    }

    @Before
    public void before() throws Exception {
        runner.admin().indices().prepareDelete("_all").execute().actionGet();
        runner.refresh();
        suggester = Suggester.builder().build(runner.client(), "AnalyzerNormalizerTest");
        suggester.createIndexIfNothing();
    }

    @Test

    }

    @Test
    public void testIndicesTimeout() {
        // Test setting indices timeout
        SuggestSettingsBuilder result = builder.indicesTimeout("10s");
        assertEquals(builder, result); // Test method chaining
        assertEquals("10s", builder.timeoutSettings.indicesTimeout);

        // Test updating indices timeout
        builder.indicesTimeout("45s");

        FLAGS[prefixFlag or frameFlag or FLAG_PADDED] =
          FLAGS[prefixFlag] + '|'.toString() + FLAGS[frameFlag] + "|PADDED"
      }
    }

    for (i in FLAGS.indices) { // Fill in holes with binary representation.
      if (FLAGS[i] == null) FLAGS[i] = BINARY[i]
    }
  }

  /**
   * Returns a human-readable representation of HTTP/2 frame headers.
   *

    @AfterClass
    public static void afterClass() throws Exception {
        runner.close();
        runner.clean();
    }

    @Before
    public void before() throws Exception {
        runner.admin().indices().prepareDelete("_all").execute().actionGet();
        runner.refresh();
        settings = Suggester.builder().build(runner.client(), id).settings();
    }

    @Test
    public void test_badWordIndexName() {

    @AfterClass
    public static void afterClass() throws Exception {
        runner.close();
        runner.clean();
    }

    @Before
    public void before() throws Exception {
        runner.admin().indices().prepareDelete("_all").execute().actionGet();
        runner.refresh();
        settings = Suggester.builder().build(runner.client(), id).settings();
    }

    @Test

import org.dbflute.exception.IllegalBehaviorStateException;
import org.dbflute.util.DfTypeUtil;
import org.opensearch.action.DocWriteResponse.Result;
import org.opensearch.action.admin.indices.refresh.RefreshResponse;
import org.opensearch.action.bulk.BulkItemResponse;
import org.opensearch.action.bulk.BulkRequestBuilder;
import org.opensearch.action.bulk.BulkResponse;