* consumption at the price of moderately increased constant factors of CPU. Only use this class
 * when there is a specific reason to prioritize memory over CPU.
 *
 * @author Louis Wasserman
 */
@J2ktIncompatible // no support for access-order mode in LinkedHashMap delegate
@GwtIncompatible // not worth using in GWT for now
@ElementTypesAreNonnullByDefault

 *
 * <p>For example, the tree
 *
 * <pre>{@code
 *        h
 *      / | \
 *     /  e  \
 *    d       g
 *   /|\      |
 *  / | \     f
 * a  b  c
 * }</pre>
 *
 * <p>can be iterated over in preorder (hdabcegf), postorder (abcdefgh), or breadth-first order
 * (hdegabcf).
 *
 * <p>Null nodes are strictly forbidden.
 *
 * <p>Because this is an abstract class, not an interface, you can't use a lambda expression to

            </tag>
          </tags>

          <!-- TODO(cpovirk): Move this to the parent after making the package-list files available there. -->
          <!-- We add the link ourselves, both so that we can choose Java 9 over the version that -source suggests and so that we can solve the JSR305 problem described below. -->
          <detectJavaApiLink>false</detectJavaApiLink>
          <offlineLinks>

@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class PeekingIteratorTest extends TestCase {

  /**
   * Version of {@link IteratorTester} that compares an iterator over a given collection of elements
   * (used as the reference iterator) against a {@code PeekingIterator} that *wraps* such an
   * iterator (used as the target iterator).
   *

            </tag>
          </tags>

          <!-- TODO(cpovirk): Move this to the parent after making the package-list files available there. -->
          <!-- We add the link ourselves, both so that we can choose Java 9 over the version that -source suggests and so that we can solve the JSR305 problem described below. -->
          <detectJavaApiLink>false</detectJavaApiLink>
          <offlineLinks>

@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class PeekingIteratorTest extends TestCase {

  /**
   * Version of {@link IteratorTester} that compares an iterator over a given collection of elements
   * (used as the reference iterator) against a {@code PeekingIterator} that *wraps* such an
   * iterator (used as the target iterator).
   *

    ImmutableSet.Builder<Field> builder = ImmutableSet.builder();
    for (Field field : cls.getDeclaredFields()) {
      /*
       * Coverage mode generates synthetic fields.  If we ever add private
       * fields, they will cause similar problems, and we may want to switch
       * this check to isAccessible().
       */
      if (!field.isSynthetic() && field.getType() == String.class) {