import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.SortedSet;

/**
 * Optional features of classes derived from {@code Collection}.
 *
 * @author George van den Driessche
 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible
public enum CollectionFeature implements Feature<Collection> {
  /**

import com.google.common.base.Supplier;
import java.util.concurrent.Callable;
import org.jspecify.annotations.Nullable;

/**
 * Static utility methods pertaining to the {@link Callable} interface.
 *
 * @author Isaac Shum
 * @since 1.0
 */
@GwtCompatible
public final class Callables {
  private Callables() {}

  /** Creates a {@code Callable} which immediately returns a preset value each time it is called. */

 * whereToDiffer} produces no observable change in performance. We want to make sure that the array
 * equals implementation is *not* short-circuiting to prevent timing-based attacks. Being fast is
 * only a secondary goal.
 *
 * @author Kurt Alfred Kluever
 */
@NullUnmarked
public class HashCodeBenchmark {

  // Use a statically configured random instance for all of the benchmarks
  private static final Random random = new Random(42);

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

/**
 * Benchmarks for various algorithms for computing the mean and/or variance.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
public class StatsBenchmark {

  enum MeanAlgorithm {
    SIMPLE {
      @Override
      double mean(double[] values) {
        double sum = 0.0;

/**
 * A generic JUnit test which tests {@code putIfAbsent} operations on a concurrent map. Can't be
 * invoked directly; please see {@link
 * com.google.common.collect.testing.ConcurrentMapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")
// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.

import com.google.common.escape.Escaper;
import com.google.common.escape.UnicodeEscaper;
import java.io.IOException;
import junit.framework.Assert;

/**
 * Extra assert methods for testing Escaper implementations.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
public final class EscaperAsserts {
  private EscaperAsserts() {}

  /**
   * Asserts that an escaper behaves correctly with respect to null inputs.
   *

import java.io.StringReader;
import java.io.Writer;
import java.util.EnumSet;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for the default implementations of {@code CharSink} methods.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class CharSinkTest extends IoTestCase {

  private static final String STRING = ASCII + I18N;

  private TestCharSink sink;

  @Override
  public void setUp() {

/**
 * A generator of {@code TestSuite} instances for testing {@code CharSink} implementations.
 * Generates tests of all methods on a {@code CharSink} given various inputs written to it.
 *
 * @author Colin Decker
 */
@AndroidIncompatible // TODO(b/230620681): Make this available (even though we won't run it).
@NullUnmarked
public class CharSinkTester extends SourceSinkTester<CharSink, String, CharSinkFactory> {

import java.util.SortedSet;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link MultimapBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public class MultimapBuilderTest extends TestCase {

  @J2ktIncompatible
  @GwtIncompatible // doesn't build without explicit type parameters on build() methods

import java.util.Spliterator;
import java.util.function.Consumer;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} backed by a non-empty {@link java.util.EnumSet}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@SuppressWarnings("serial") // we're overriding default serialization
final class ImmutableEnumSet<E extends Enum<E>> extends ImmutableSet<E> {