public class MultisetTestSuiteBuilder<E>
    extends AbstractCollectionTestSuiteBuilder<MultisetTestSuiteBuilder<E>, E> {
  public static <E> MultisetTestSuiteBuilder<E> using(TestMultisetGenerator<E> generator) {
    return new MultisetTestSuiteBuilder<E>().usingGenerator(generator);
  }

  public enum NoRecurse implements Feature<Void> {
    NO_ENTRY_SET;

    @Override
    public Set<Feature<? super Void>> getImpliedFeatures() {

 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//

-   Read the [Code of Conduct](CODE_OF_CONDUCT.md).
-   Ensure you have signed the
    [Contributor License Agreement (CLA)](https://cla.developers.google.com/).
-   Check if your changes are consistent with the
    [guidelines](#general-guidelines-and-philosophy-for-contribution).
-   Changes are consistent with the [Coding Style](#c-coding-style).
-   Run the [unit tests](#running-unit-tests).

## How to become a contributor and submit your own code

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.ListMultimap;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A generator for {@code ListMultimap} implementations based on test data.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public interface TestListMultimapGenerator<K extends @Nullable Object, V extends @Nullable Object>

          OneSizeTestContainerGenerator<Map<K, V>, Entry<K, V>> mapGenerator) {
    TestContainerGenerator<Map<K, V>, Entry<K, V>> generator = mapGenerator.getInnerGenerator();
    if (generator instanceof TestSortedMapGenerator
        && ((TestSortedMapGenerator<K, V>) generator).create().keySet() instanceof SortedSet) {
      return new MapSortedKeySetGenerator<>(mapGenerator);
    } else {

   * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might
   * be declared as a {@code List}.
   *
   * <p>Note also that serialization is not in general required to return an object that is
   * {@linkplain Object#equals equal} to the original, nor is it required to return even an object
   * of the same class. For example, if sublists of {@code MyList} instances were serializable,

        ERROR, //
        WARNING //
    }

    /**
     * Gets the hint about the source of the problem. While the syntax of this hint is unspecified and depends on the
     * creator of the problem, the general expectation is that the hint provides sufficient information to the user to
     * track the problem back to its origin. A concrete example for such a source hint can be the file path or URL from
     * which the settings were read.

import org.jspecify.annotations.Nullable;

/**
 * To be implemented by test generators that can produce test subjects without requiring any
 * parameters.
 *
 * @param <T> the type created by this generator.
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked
public interface TestSubjectGenerator<T extends @Nullable Object> {
  T createTestSubject();

public final class NavigableSetTestSuiteBuilder<E> extends SortedSetTestSuiteBuilder<E> {
  public static <E> NavigableSetTestSuiteBuilder<E> using(TestSortedSetGenerator<E> generator) {
    NavigableSetTestSuiteBuilder<E> builder = new NavigableSetTestSuiteBuilder<>();
    builder.usingGenerator(generator);
    return builder;
  }

  @Override
  protected List<TestSuite> createDerivedSuites(