* collector by only using a constant number of internal objects.
 *
 * <p>If there are no removals, then iteration order for the {@link #entrySet}, {@link #keySet}, and
 * {@link #values} views is the same as insertion order. Any removal invalidates any ordering
 * guarantees.
 *
 * <p>This class should not be assumed to be universally superior to {@code java.util.HashMap}.

import com.google.common.annotations.GwtCompatible;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.jspecify.annotations.NullMarked;

/**
 * Implementation helper for {@link TestMapGenerator} for use with maps of strings.
 *
 * @author Chris Povirk
 * @author Jared Levy
 * @author George van den Driessche
 */
@GwtCompatible
@NullMarked

import com.google.common.collect.testing.features.CollectionSize;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code addAll(Collection)} operations on a list. Can't be
 * invoked directly; please see {@link com.google.common.collect.testing.ListTestSuiteBuilder}.
 *
 * @author Chris Povirk
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

import com.google.caliper.Param;
import com.google.caliper.api.SkipThisScenarioException;
import java.util.List;
import org.jspecify.annotations.NullUnmarked;

/**
 * Quick and dirty benchmark of {@link Throwables#lazyStackTrace(Throwable)}. We benchmark a "caller
 * finder" implementation that might be used in a logging framework.
 */
@NullUnmarked
public class LazyStackTraceBenchmark {
  @Param({"20", "200", "2000"})

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Preconditions;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} with exactly one element.
 *
 * @author Kevin Bourrillion
 * @author Nick Kralevich
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import java.util.Map;

/**
 * An implementation of {@link ImmutableTable} that holds a single cell.
 *
 * @author Gregory Kick
 */
@GwtCompatible
final class SingletonImmutableTable<R, C, V> extends ImmutableTable<R, C, V> {
  final R singleRowKey;
  final C singleColumnKey;

import com.google.common.annotations.J2ktIncompatible;
import java.util.Collections;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/** Implementation of an {@link Optional} containing a reference. */
@GwtCompatible
final class Present<T> extends Optional<T> {
  private final T reference;

  Present(T reference) {
    this.reference = reference;
  }

  @Override

import com.google.common.collect.ImmutableBiMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import org.jspecify.annotations.NullMarked;

/**
 * Generators of various {@link com.google.common.collect.BiMap}s and derived collections.
 *
 * @author Jared Levy
 * @author Hayward Chan
 */
@GwtCompatible
@NullMarked
public class BiMapGenerators {

import com.google.caliper.Param;
import com.google.caliper.api.SkipThisScenarioException;
import java.util.List;
import org.jspecify.annotations.NullUnmarked;

/**
 * Quick and dirty benchmark of {@link Throwables#lazyStackTrace(Throwable)}. We benchmark a "caller
 * finder" implementation that might be used in a logging framework.
 */
@NullUnmarked
public class LazyStackTraceBenchmark {
  @Param({"20", "200", "2000"})

import com.google.common.collect.testing.features.CollectionSize;
import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code peek()} operations on a queue. Can't be invoked directly;
 * please see {@link com.google.common.collect.testing.CollectionTestSuiteBuilder}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")