import java.util.Map;

import org.opensearch.search.rescore.RescorerBuilder;

/**
 * Interface for query rescoring implementations.
 */
public interface QueryRescorer {
    /**
     * Evaluates the rescorer with the given parameters.
     *
     * @param params the parameters for rescoring
     * @return the rescorer builder
     */
    RescorerBuilder<?> evaluate(final Map<String, Object> params);

import org.opensearch.search.rescore.RescorerBuilder;

/**
 * Learning to Rank query rescorer implementation.
 */
public class LtrQueryRescorer implements QueryRescorer {

    /**
     * Default constructor.
     */
    public LtrQueryRescorer() {
        // Default constructor
    }

    @Override
    public RescorerBuilder<?> evaluate(final Map<String, Object> params) {

     * @return an array of rescorer builders, filtered to exclude null values
     */
    public RescorerBuilder<?>[] getRescorers(final Map<String, Object> params) {
        return queryRescorerList.stream().map(r -> r.evaluate(params)).filter(b -> b != null).toArray(n -> new RescorerBuilder<?>[n]);
    }

    /**
     * Adds a query rescorer for post-processing search results.