* list of size {@code m x n x p}, its actual memory consumption is much smaller. When the
   * cartesian product is constructed, the input lists are merely copied. Only as the resulting list
   * is iterated are the individual lists created, and these are not retained after iteration.
   *

    List<String> actual = Lists.newArrayList(filtered);
    assertEquals(expected, actual);
  }

  public void testFilterMatchAll() {
    Iterator<String> unfiltered = Lists.newArrayList("foo", "bar").iterator();
    Iterator<String> filtered = filter(unfiltered, Predicates.alwaysTrue());
    List<String> expected = Lists.newArrayList("foo", "bar");
    List<String> actual = Lists.newArrayList(filtered);

 */

package com.google.common.collect.testing;

import static com.google.common.collect.Lists.newArrayList;
import static com.google.common.collect.testing.IteratorFeature.MODIFIABLE;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

  public void testPeekingIteratorBehavesLikeIteratorOnThreeElementIterable() {
    actsLikeIteratorHelper(Lists.newArrayList("A", "B", "C"));
  }

  @GwtIncompatible // works but takes 5 minutes to run
  public void testPeekingIteratorAcceptsNullElements() {
    actsLikeIteratorHelper(Lists.<@Nullable String>newArrayList(null, "A", null));
  }

  public void testPeekOnEmptyList() {

    assertEquals(Lists.newArrayList("a", "b"), list);
  }

  public void testCreation_threeElements() {
    List<String> list = ImmutableList.of("a", "b", "c");
    assertEquals(Lists.newArrayList("a", "b", "c"), list);
  }

  public void testCreation_fourElements() {
    List<String> list = ImmutableList.of("a", "b", "c", "d");
    assertEquals(Lists.newArrayList("a", "b", "c", "d"), list);
  }

  public void testPeekingIteratorBehavesLikeIteratorOnThreeElementIterable() {
    actsLikeIteratorHelper(Lists.newArrayList("A", "B", "C"));
  }

  @GwtIncompatible // works but takes 5 minutes to run
  public void testPeekingIteratorAcceptsNullElements() {
    actsLikeIteratorHelper(Lists.<@Nullable String>newArrayList(null, "A", null));
  }

  public void testPeekOnEmptyList() {

    assertEquals(Lists.newArrayList("a", "b"), list);
  }

  public void testCreation_threeElements() {
    List<String> list = ImmutableList.of("a", "b", "c");
    assertEquals(Lists.newArrayList("a", "b", "c"), list);
  }

  public void testCreation_fourElements() {
    List<String> list = ImmutableList.of("a", "b", "c", "d");
    assertEquals(Lists.newArrayList("a", "b", "c", "d"), list);
  }

    List<@Nullable Integer> list2 = Lists.newArrayList(1);
    List<@Nullable Integer> list3 = Lists.newArrayList(1, 1);
    List<@Nullable Integer> list4 = Lists.newArrayList(1, 2);
    List<@Nullable Integer> list5 = Lists.newArrayList(1, null, 2);
    List<@Nullable Integer> list6 = Lists.newArrayList(2);
    List<@Nullable Integer> list7 = Lists.newArrayList(nullInt);

    List<@Nullable Integer> list2 = Lists.newArrayList(1);
    List<@Nullable Integer> list3 = Lists.newArrayList(1, 1);
    List<@Nullable Integer> list4 = Lists.newArrayList(1, 2);
    List<@Nullable Integer> list5 = Lists.newArrayList(1, null, 2);
    List<@Nullable Integer> list6 = Lists.newArrayList(2);
    List<@Nullable Integer> list7 = Lists.newArrayList(nullInt);

/**
 * Implementation of {@link Lists#cartesianProduct(List)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class CartesianList<E> extends AbstractList<List<E>> implements RandomAccess {

  private final transient ImmutableList<List<E>> axes;
  private final transient int[] axesSizeProduct;

  static <E> List<List<E>> create(List<? extends List<? extends E>> lists) {