Iterable<String> iterable = asList("a", "b");
    Iterator<String> cycle = Iterators.cycle(iterable);
    cycle.next();
    assertThrows(UnsupportedOperationException.class, () -> cycle.remove());
  }

  public void testCycleRemoveAfterHasNext() {
    Iterable<String> iterable = Lists.newArrayList("a");
    Iterator<String> cycle = Iterators.cycle(iterable);
    assertTrue(cycle.hasNext());

  }

  private static boolean isEmpty(Iterable<?> iterable) {
    return iterable instanceof Collection
        ? ((Collection<?>) iterable).isEmpty()
        : !iterable.iterator().hasNext();
  }

  public static void assertEmpty(Iterable<?> iterable) {
    if (!isEmpty(iterable)) {
      fail("Not true that " + iterable + " is empty");
    }
  }

    TypeToken<ImmutableList<Integer>[]> type = new TypeToken<ImmutableList<Integer>[]>() {};
    ImmutableTypeToInstanceMap<Iterable<?>[]> map =
        ImmutableTypeToInstanceMap.<Iterable<?>[]>builder().put(type, array).build();
    assertEquals(1, map.size());
    // Redundant cast works around a javac bug.
    assertThat((Iterable<?>[]) map.getInstance(type)).asList().containsExactly(array[0]);
  }

  public void testWildcardType() {

//      from the plugin archive.
// TODO this will be the class that people get in IDEs to modify

/**
 * MavenExecutionPlan
 */
public class MavenExecutionPlan implements Iterable<ExecutionPlanItem> {

    /*
      At the moment, this class is totally immutable, and this is in line with thoughts about the
      pre-calculated execution plan that stays the same during the execution.

    return 0;
  }

  @Override
  public <E extends @Nullable Object> List<E> sortedCopy(Iterable<E> iterable) {
    return Lists.newArrayList(iterable);
  }

  @Override
  public <E> ImmutableList<E> immutableSortedCopy(Iterable<E> iterable) {
    return ImmutableList.copyOf(iterable);
  }

  @SuppressWarnings("unchecked")
  @Override
  public <S extends @Nullable Object> Ordering<S> reverse() {

    Iterable<Long> iterable = iterable(Collections.<Long>emptySet());
    assertThat(ImmutableLongArray.copyOf(iterable)).isSameInstanceAs(ImmutableLongArray.of());
  }

  public void testCopyOf_iterable_notCollection_nonempty() {
    List<Long> list = Arrays.asList(0L, 1L, 3L);
    ImmutableLongArray iia = ImmutableLongArray.copyOf(iterable(list));
    list.set(2, 2L);

     *
     * @return The number of {@link PropertyDesc}
     */
    int getPropertyDescSize();

    /**
     * Returns an {@link Iterable} of {@link PropertyDesc}.
     *
     * @return An {@link Iterable} of {@link PropertyDesc}
     */
    Iterable<PropertyDesc> getPropertyDescs();

    /**
     * Returns whether the {@link FieldDesc} exists.
     *
     * @param fieldName

     * @return an {@link Iterable} wrapping a {@link ClassLoaderIterator}
     */
    public static Iterable<ClassLoader> iterable(final ClassLoader classLoader) {
        return () -> new ClassLoaderIterator(classLoader);
    }

    /**
     * Constructs an instance.
     *
     * @param classLoader the class loader (must not be {@literal null})
     */

  protected ListIteratorTester(
      int steps,
      Iterable<E> elementsToInsert,
      Iterable<? extends IteratorFeature> features,
      Iterable<E> expectedElements,
      int startIndex) {
    super(steps, elementsToInsert, features, expectedElements, KnownOrder.KNOWN_ORDER, startIndex);
  }

  @Override
  protected final Iterable<? extends Stimulus<E, ? super ListIterator<E>>> getStimulusValues() {

    throw ArrayIndexOutOfBoundsException("length=$arrayLength, offset=$offset, count=$offset")
  }
}

internal fun <T> interleave(
  a: Iterable<T>,
  b: Iterable<T>,
): List<T> {
  val ia = a.iterator()
  val ib = b.iterator()

  return buildList {
    while (ia.hasNext() || ib.hasNext()) {
      if (ia.hasNext()) {
        add(ia.next())
      }