final String index1 = "test-multi-index-001";
        final String index2 = "test-multi-index-002";
        final String aliasName = "test-multi-alias";

        // Create first index with alias
        client.admin().indices().prepareCreate(index1).addAlias(new Alias(aliasName)).execute().actionGet();

        // Create second index and add to same alias

        fesenClient.setSearchPreference("_local");

        final SearchRequestBuilder result1 = fesenClient.prepareSearch("index1");
        final SearchRequestBuilder result2 = fesenClient.prepareStreamSearch("index1");

        // Both should use the same underlying mechanism
        verify(mockClient, times(2)).prepareSearch(any(String[].class));

import org.codelibs.fess.util.ComponentUtil;
import org.opensearch.common.lucene.search.function.CombineFunction;
import org.opensearch.index.query.BoolQueryBuilder;
import org.opensearch.index.query.QueryBuilders;
import org.opensearch.index.query.functionscore.FunctionScoreQueryBuilder;
import org.opensearch.index.query.functionscore.ScoreFunctionBuilders;
import org.opensearch.search.sort.SortBuilders;

import jakarta.annotation.PostConstruct;

    });
```

## Advanced Usage

### Index from Existing Documents

```java
import org.codelibs.fess.suggest.index.contents.document.ESSourceReader;

// Index suggestions from existing Elasticsearch documents
DocumentReader reader = new ESSourceReader(
    client,
    suggester.settings(),
    "content-index",        // source index
    "document"             // document type
);

import org.codelibs.fess.suggest.entity.ElevateWord;
import org.codelibs.fess.suggest.entity.SuggestItem;
import org.codelibs.fess.suggest.index.SuggestIndexResponse;
import org.codelibs.fess.suggest.index.contents.document.ESSourceReader;
import org.codelibs.fess.suggest.index.contents.querylog.QueryLog;
import org.codelibs.fess.suggest.index.contents.querylog.QueryLogReader;
import org.codelibs.fess.suggest.request.popularwords.PopularWordsResponse;

        final int index = indexOf(array, obj);
        if (index < 0) {
            return array;
        }
        @SuppressWarnings("unchecked")
        final T[] newArray = (T[]) Array.newInstance(array.getClass().getComponentType(), array.length - 1);
        if (index > 0) {
            System.arraycopy(array, 0, newArray, 0, index);
        }
        if (index < array.length - 1) {

import org.codelibs.fess.suggest.index.contents.ContentsParser;
import org.codelibs.fess.suggest.index.contents.DefaultContentsParser;
import org.codelibs.fess.suggest.index.contents.document.DocumentReader;
import org.codelibs.fess.suggest.index.contents.querylog.QueryLog;
import org.codelibs.fess.suggest.index.contents.querylog.QueryLogReader;
import org.codelibs.fess.suggest.index.writer.SuggestIndexWriter;

                int index = userInfo.indexOf(':');
                user = index != -1 ? userInfo.substring(0, index) : userInfo;
                if (index != -1) {
                    password = userInfo.substring(index + 1);
                }
                index = user.indexOf('\\');
                if (index == -1) {
                    index = user.indexOf('/');
                }

        SuggestIndexer indexer = suggester.indexer();

        assertNotNull(indexer.setIndexName("test-index"));
        assertNotNull(indexer.setSupportedFields(new String[] { "field1", "field2" }));
        assertNotNull(indexer.setTagFieldNames(new String[] { "tag1", "tag2" }));
        assertNotNull(indexer.setRoleFieldName("role"));
        assertNotNull(indexer.setReadingConverter(null));

                buf.append(ch);
            }
        }
        if (buf.indexOf("yy") == -1) {
            final int pos = buf.indexOf("y");
            if (pos != -1) {
                buf.replace(pos, pos + 1, "yy");
            }
        }
        if (buf.indexOf("MM") == -1) {
            final int pos = buf.indexOf("M");
            if (pos != -1) {
                buf.replace(pos, pos + 1, "MM");