* generally be avoided. Prefer {@link Interners#newWeakInterner} or another {@code Interner}
 * implementation even for {@code String} interning.
 *
 * @author Kevin Bourrillion
 * @since 3.0
 */
@DoNotMock("Use Interners.new*Interner")
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public interface Interner<E> {
  /**

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.testing.NullPointerTester;
import java.util.Set;
import junit.framework.TestCase;

/**
 * Unit test for {@link Primitives}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(emulated = true)
public class PrimitivesTest extends TestCase {
  public void testIsWrapperType() {
    assertThat(Primitives.isWrapperType(Void.class)).isTrue();

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

/**
 * A generator using sample elements whose hash codes all collide badly.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestCollidingSetGenerator implements TestSetGenerator<Object> {
  @Override
  public SampleElements<Object> samples() {

import java.util.Collection;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Creates collections, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TestCollectionGenerator<E extends @Nullable Object>

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

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

 * limitations under the License.
 */

package com.google.common.testing;

import com.google.common.annotations.GwtCompatible;

/**
 * An object that can perform a {@link #tearDown} operation.
 *
 * @author Kevin Bourrillion
 * @since 10.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface TearDown {
  /**
   * Performs a <b>single</b> tear-down operation. See test-libraries-for-java's {@code

 * 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 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;
  }

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;
  }

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.testing.NullPointerTester;
import java.util.Set;
import junit.framework.TestCase;

/**
 * Unit test for {@link Primitives}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(emulated = true)
public class PrimitivesTest extends TestCase {
  public void testIsWrapperType() {
    assertThat(Primitives.isWrapperType(Void.class)).isTrue();