*
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/CollectionUtilitiesExplained#multisets">{@code
 * Multisets}</a>.
 *
 * @author Kevin Bourrillion
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Multisets {
  private Multisets() {}

  /**

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@code Sets}.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class SetsTest extends TestCase {

  private static final IteratorTester.KnownOrder KNOWN_ORDER =

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@code Iterators}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class IteratorsTest extends TestCase {

  @J2ktIncompatible
  @GwtIncompatible // suite
  public static Test suite() {

 * absolutely necessary.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/CollectionUtilitiesExplained#iterables">{@code
 * Iterables}</a>.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class Iterables {
  private Iterables() {}

 *
 * <h3>More information</h3>
 *
 * <p>See the Guava User Guide on <a
 * href="https://github.com/google/guava/wiki/PreconditionsExplained">using {@code
 * Preconditions}</a>.
 *
 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public final class Preconditions {
  private Preconditions() {}

  private interface Impossible {}

  /**

import com.google.common.annotations.GwtCompatible;
import java.util.Set;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates sets, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestSetGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {
  @Override
  Set<E> create(Object... elements);

import com.google.common.annotations.J2ktIncompatible;
import javax.annotation.CheckForNull;

/**
 * Unchecked version of {@link java.util.concurrent.TimeoutException}.
 *
 * @author Kevin Bourrillion
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public class UncheckedTimeoutException extends RuntimeException {
  public UncheckedTimeoutException() {}

import java.io.Serializable;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Simple base class to verify that we handle generics correctly.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
public class BaseComparable implements Comparable<BaseComparable>, Serializable {
  private final String s;

  public BaseComparable(String s) {
    this.s = s;
  }

 * interacting with this class directly.
 *
 * <p><b>Warning:</b> this interface can only be used to measure elapsed time, not wall time.
 *
 * @author Kevin Bourrillion
 * @since 10.0 (<a href="https://github.com/google/guava/wiki/Compatibility">mostly
 *     source-compatible</a> since 9.0)
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class Ticker {

import com.google.common.collect.testing.SampleElements.Strings;
import java.util.List;
import java.util.Set;

/**
 * Create string sets for collection tests.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestStringSetGenerator implements TestSetGenerator<String> {
  @Override
  public SampleElements<String> samples() {