String[][] readings = new String[2][];
readings[0] = new String[]{"kensaku", "engine"};
readings[1] = new String[]{"search", "injin"};

String[] tags = new String[]{"technology", "search"};
String[] roles = new String[]{"admin", "user"};

SuggestItem item = new SuggestItem(
    new String[]{"Search Engine", "検索エンジン"}, // text variations
    readings,                                      // pronunciation readings

│   └── service/             # Core services
├── fess-crawler-lasta/       # LastaFlute DI integration
└── fess-crawler-opensearch/  # OpenSearch backend
```

### Key Components

#### Core Engine
- **Crawler**: Main orchestrator managing crawl execution
- **CrawlerContext**: Execution context and configuration
- **CrawlerThread**: Individual crawler thread implementation

#### Client Architecture

import org.opensearch.common.unit.TimeValue;
import org.opensearch.core.action.ActionListener;
import org.opensearch.core.action.ActionResponse;
import org.opensearch.index.IndexNotFoundException;
import org.opensearch.index.engine.VersionConflictEngineException;
import org.opensearch.index.query.QueryBuilder;
import org.opensearch.search.Scroll;
import org.opensearch.search.SearchHit;
import org.opensearch.threadpool.ThreadPool;

import org.codelibs.fess.suggest.util.SuggestUtil;
import org.opensearch.common.Nullable;

/**
 * The SuggestItem class represents an item used for suggestions in the Fess search engine.
 * It contains various attributes such as text, readings, fields, tags, roles, languages, kinds, and frequencies.