import java.util.List;
import java.util.NoSuchElementException;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@link PeekingIterator}.
 *
 * @author Mick Killianey
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class PeekingIteratorTest extends TestCase {

  /**

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

/**
 * Unit test for {@link NullPointerTester}.
 *
 * @author Kevin Bourrillion
 * @author Mick Killianey
 */
@SuppressWarnings("CheckReturnValue")
public class NullPointerTesterTest extends TestCase {

  /** Non-NPE RuntimeException. */
  public static class FooException extends RuntimeException {

import java.util.List;
import java.util.NoSuchElementException;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;

/**
 * Unit test for IteratorTester.
 *
 * @author Mick Killianey
 */
@GwtCompatible
@SuppressWarnings("serial") // No serialization is used in this test
public class IteratorTesterTest extends TestCase {

  public void testCanCatchDifferentLengthOfIteration() {

import java.util.List;
import java.util.NoSuchElementException;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Unit test for {@link PeekingIterator}.
 *
 * @author Mick Killianey
 */
@SuppressWarnings("serial") // No serialization is used in this test
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class PeekingIteratorTest extends TestCase {

  /**

import java.util.List;
import java.util.NoSuchElementException;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;

/**
 * Unit test for IteratorTester.
 *
 * @author Mick Killianey
 */
@GwtCompatible
@SuppressWarnings("serial") // No serialization is used in this test
public class IteratorTesterTest extends TestCase {

  public void testCanCatchDifferentLengthOfIteration() {

 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/CollectionHelpersExplained#peekingiterator">{@code
 * PeekingIterator}</a>.
 *
 * @author Mick Killianey
 * @since 2.0
 */
@DoNotMock("Use Iterators.peekingIterator")
@GwtCompatible
@ElementTypesAreNonnullByDefault
public interface PeekingIterator<E extends @Nullable Object> extends Iterator<E> {
  /**