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

    }

    @Override
    public boolean offer(T o) {
      return standardOffer(o);
    }

    @Override
    public @Nullable T peek() {
      return standardPeek();
    }

    @Override
    public @Nullable T poll() {
      return standardPoll();
    }
  }

  @AndroidIncompatible // test-suite builders
  public static Test suite() {

    checkNotClosed();
    target.append(c);
    return this;
  }

  @Override
  public Writer append(@Nullable CharSequence charSeq) throws IOException {
    checkNotClosed();
    target.append(charSeq);
    return this;
  }

  @Override
  public Writer append(@Nullable CharSequence charSeq, int start, int end) throws IOException {
    checkNotClosed();
    target.append(charSeq, start, end);

    static final class PluginInfo {
        @Nonnull
        final String groupId;

        @Nonnull
        private final String artifactId;

        @Nullable
        private final String goalPrefix;

        @Nullable
        private final String name;

        PluginInfo(String groupId, String artifactId, String goalPrefix, String name) {
            this.groupId = groupId;

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates multisets, containing sample elements, to be tested.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public interface TestMultisetGenerator<E extends @Nullable Object>
    extends TestCollectionGenerator<E> {
  @Override
  Multiset<E> create(Object... elements);

import java.lang.ref.WeakReference;
import java.util.Iterator;
import java.util.NoSuchElementException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@code AbstractIterator}.
 *
 * @author Kevin Bourrillion
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible
@NullMarked

import java.lang.ref.WeakReference;
import java.util.Iterator;
import java.util.NoSuchElementException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@code AbstractIterator}.
 *
 * @author Kevin Bourrillion
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible
@NullMarked

import static com.google.common.base.Preconditions.checkNotNull;
import static java.lang.Math.min;

import com.google.common.annotations.GwtCompatible;
import java.util.Map;
import org.jspecify.annotations.Nullable;

/**
 * A {@link UnicodeEscaper} that uses an array to quickly look up replacement characters for a given
 * code point. An additional safe range is provided that determines whether code points without

    }

    @Override
    public @Nullable V edgeValueOrDefault(N nodeU, N nodeV, @Nullable V defaultValue) {
      return delegate().edgeValueOrDefault(nodeV, nodeU, defaultValue); // transpose
    }

    @Override
    public @Nullable V edgeValueOrDefault(EndpointPair<N> endpoints, @Nullable V defaultValue) {
      return delegate().edgeValueOrDefault(transpose(endpoints), defaultValue);

   * defaultValue)}.
   *
   * @throws IllegalArgumentException if {@code nodeU} or {@code nodeV} is not an element of this
   *     graph
   */
  @Nullable V edgeValueOrDefault(N nodeU, N nodeV, @Nullable V defaultValue);

  /**
   * Returns the value of the edge that connects {@code endpoints} (in the order, if any, specified