Map<@Nullable String, String> hashmap = new HashMap<>();
    hashmap.put("foo", "bar");
    hashmap.put(null, "baz");

    assertEquals(hashmap.toString(), Maps.toStringImpl(hashmap));
  }

  public void testToStringImplWithNullValues() throws Exception {
    Map<String, @Nullable String> hashmap = new HashMap<>();
    hashmap.put("foo", "bar");
    hashmap.put("baz", null);

    Map<@Nullable String, String> hashmap = new HashMap<>();
    hashmap.put("foo", "bar");
    hashmap.put(null, "baz");

    assertEquals(hashmap.toString(), Maps.toStringImpl(hashmap));
  }

  public void testToStringImplWithNullValues() throws Exception {
    Map<String, @Nullable String> hashmap = new HashMap<>();
    hashmap.put("foo", "bar");
    hashmap.put("baz", null);

    }

    /**
     * Creates and returns a new instance of {@link HashMap}.
     *
     * @param <K> the key type of {@link HashMap}
     * @param <V> the value type of {@link HashMap}
     * @return a new instance of {@link HashMap}
     * @see HashMap#HashMap()
     */
    public static <K, V> HashMap<K, V> newHashMap() {
        return new HashMap<>();
    }

    /**

import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.URLDecoder;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.UUID;
import java.util.function.Supplier;

import org.apache.commons.lang3.ArrayUtils;

import javax.xml.stream.XMLStreamException;

import java.io.IOException;
import java.time.Duration;
import java.time.Instant;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

            return;
        }

        Map<String, Plugin> plugins = new HashMap<>();
        Map<String, String> versions = new HashMap<>();
        Map<String, String> managedVersions = new HashMap<>();

        for (int i = lineage.size() - 1; i >= 0; i--) {
            Model model = lineage.get(i).getModel();
            Build build = model.getBuild();

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import java.io.File;
import java.util.Arrays;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;

    protected boolean useGoogleOffOn = true;

    /** Map storing field pruning rules */
    protected Map<String, Boolean> fieldPrunedRuleMap = new HashMap<>();

    /** Cache for storing parsed pruned tags by configuration ID */
    protected Map<String, PrunedTag[]> prunedTagsCache = new HashMap<>();

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

    /**

import java.io.IOException;
import java.io.Writer;
import java.nio.file.Path;
import java.util.AbstractSequentialList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Objects;
import java.util.Properties;

    /** Initial facet parameter mappings */
    protected final Map<String, String> initFacetParamMap = new HashMap<>();

    /** Initial geographic parameter mappings */
    protected final Map<String, String> initGeoParamMap = new HashMap<>();

    /** List of facet query views */
    protected final List<FacetQueryView> facetQueryViewList = new ArrayList<>();