private static final class AlwaysEqual extends Ordering<@Nullable Object>
      implements Serializable {
    private static final AlwaysEqual INSTANCE = new AlwaysEqual();

    @Override
    @SuppressWarnings("UnusedVariable") // intentionally weird Comparator
    public int compare(@Nullable Object o1, @Nullable Object o2) {
      return 0;
    }

    @Override

import static junit.framework.Assert.fail;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeoutException;
import org.jspecify.annotations.Nullable;

/** Methods factored out so that they can be emulated differently in GWT. */
final class TestPlatform {
  static void verifyGetOnPendingFuture(Future<?> future) {
    try {
      future.get();
      fail();

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Collection;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Base class for collection testers.
 *
 * @param <E> the element type of the collection to be tested.
 * @author Kevin Bourrillion
 */
@GwtCompatible

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.logging.Handler;
import java.util.logging.LogRecord;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests may use this to intercept messages that are logged by the code under test. Example:
 *
 * <pre>
 *   TestLogHandler handler;
 *
 *   protected void setUp() throws Exception {

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Collection;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Base class for collection testers.
 *
 * @param <E> the element type of the collection to be tested.
 * @author Kevin Bourrillion
 */
@GwtCompatible

import java.util.Collection;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Immutable;
import org.apache.maven.api.annotations.Nonnull;
import org.apache.maven.api.annotations.Nullable;

/**
 * {@code ArtifactCoordinates} completed with information about how the artifact will be used.
 * This information includes the dependency type (main classes, test classes, <i>etc.</i>),

import com.google.common.collect.testing.WrongType;
import com.google.common.collect.testing.features.CollectionFeature;
import com.google.common.collect.testing.features.CollectionSize;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Common parent class for {@link ListIndexOfTester} and {@link ListLastIndexOfTester}.
 *
 * @author Chris Povirk
 */
@GwtCompatible

     * @param language the language of the sources to return, or {@code null} for all languages
     */
    @Nonnull
    Stream<SourceRoot> getEnabledSourceRoots(
            @Nonnull Project project, @Nullable ProjectScope scope, @Nullable Language language);

    /**
     * Adds the given source to the given project.
     * If a source already exists for the given scope, language and directory,

import com.google.errorprone.annotations.OverridingMethodsMustInvokeSuper;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Base class for testers of classes (including {@link Collection} and {@link java.util.Map Map})
 * that contain elements.
 *
 * @param <C> the type of the container

import java.util.List;
import java.util.Set;
import java.util.logging.Logger;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.Nullable;

/**
 * Creates, based on your criteria, a JUnit test suite that exhaustively tests the object generated
 * by a G, selecting appropriate tests by matching them against specified features.
 *