protected String clusterName = "fesen";

    /** List of rewrite rules for document settings */
    protected final List<UnaryOperator<String>> docSettingRewriteRuleList = new ArrayList<>();

    /** List of rewrite rules for document mappings */
    protected final List<UnaryOperator<String>> docMappingRewriteRuleList = new ArrayList<>();

    /** Whether to use pipelines for document processing */

import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.RandomAccess;
import java.util.Spliterator;
import java.util.function.Consumer;
import java.util.function.UnaryOperator;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/**
 * A {@link List} whose contents will never change, with many other important properties detailed at
 * {@link ImmutableCollection}.

import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.function.UnaryOperator;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import javax.xml.xpath.XPathEvaluationResult;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathNodes;