*     a provided list is null
   * @since 19.0
   */
  public static <B> List<List<B>> cartesianProduct(List<? extends List<? extends B>> lists) {
    return CartesianList.create(lists);
  }

  /**
   * Returns every possible list that can be formed by choosing one element from each of the given

    assertEquals(asList(1, 4, 7, 8, 9, 10), newArrayList(result));
    assertEquals("[1, 4, 7, 8, 9, 10]", result.toString());
  }

  public void testConcatNullPointerException() {
    List<Integer> list1 = newArrayList(1);
    List<Integer> list2 = newArrayList(4);

    assertThrows(NullPointerException.class, () -> Iterables.concat(list1, null, list2));
  }

    assertEquals(asList(1, 4, 7, 8, 9, 10), newArrayList(result));
    assertEquals("[1, 4, 7, 8, 9, 10]", result.toString());
  }

  public void testConcatNullPointerException() {
    List<Integer> list1 = newArrayList(1);
    List<Integer> list2 = newArrayList(4);

    assertThrows(NullPointerException.class, () -> Iterables.concat(list1, null, list2));
  }

    assertEquals(list, newArrayList(Iterators.limit(list.iterator(), 2)));

    list.add("pants");
    assertFalse(Iterators.limit(list.iterator(), 0).hasNext());
    assertEquals(ImmutableList.of("cool"), newArrayList(Iterators.limit(list.iterator(), 1)));
    assertEquals(list, newArrayList(Iterators.limit(list.iterator(), 2)));
    assertEquals(list, newArrayList(Iterators.limit(list.iterator(), 3)));
  }

    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 testCreation_fiveElements() {
    List<String> list = ImmutableList.of("a", "b", "c", "d", "e");

  private final transient int[] axesSizeProduct;

  static <E> List<List<E>> create(List<? extends List<? extends E>> lists) {
    ImmutableList.Builder<List<E>> axesBuilder = new ImmutableList.Builder<>(lists.size());
    for (List<? extends E> list : lists) {
      List<E> copy = ImmutableList.copyOf(list);
      if (copy.isEmpty()) {
        return ImmutableList.of();
      }
      axesBuilder.add(copy);
    }

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;
import java.util.NoSuchElementException;

    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 testCreation_fiveElements() {
    List<String> list = ImmutableList.of("a", "b", "c", "d", "e");

  /** Regression test for b/4124577 */
  public void testRegression_dataCorruption() {
    int size = 8;
    List<Integer> expected = createOrderedList(size);
    MinMaxPriorityQueue<Integer> q = MinMaxPriorityQueue.create(expected);
    List<Integer> contents = new ArrayList<>(expected);
    List<Integer> elements = Lists.newArrayListWithCapacity(size);
    while (!q.isEmpty()) {
      assertThat(q).containsExactlyElementsIn(contents);

    @Override
    protected void verify(List<T> elements) {
      // verify same objects were removed from reference and target
      assertEquals(elements, targetList);
    }
  }

  private <T extends @Nullable Object> void actsLikeIteratorHelper(List<T> list) {
    // Check with modifiable copies of the list
    new PeekingIteratorTester<T>(list).test();

    // Check with unmodifiable lists
    new IteratorTester<T>(