/**
   * Indicates that a collection disallows certain elements (other than {@code null}, whose validity
   * as an element is indicated by the presence or absence of {@link #ALLOWS_NULL_VALUES}). From the
   * documentation for {@link Collection}:
   *
   * <blockquote>
   *
   * "Some collection implementations have restrictions on the elements that they may contain. For

/**
 * An {@link Iterator} that returns a single value.
 *
 * @author koichik
 * @param <E> the element type
 */
public class SingleValueIterator<E> implements Iterator<E> {

    /** The only value returned by the iterator. */
    protected final E value;

    /** {@literal true} if the iterator has more elements. */
    protected boolean hasNext = true;

    /**

   * contains(). Verify that these sets are consistent with the elements of their iterator.
   */
  @CanIgnoreReturnValue
  static <T> Set<T> sanityCheckSet(Set<T> set) {
    assertThat(set).hasSize(Iterators.size(set.iterator()));
    for (Object element : set) {
      assertThat(set).contains(element);
    }
    assertThat(set).doesNotContain(new Object());

            UpgradeContext context, Document pomDocument) {
        Element root = pomDocument.root();

        // Extract direct values
        String groupId = root.childTextTrimmed(MavenPomElements.Elements.GROUP_ID);
        String artifactId = root.childTextTrimmed(MavenPomElements.Elements.ARTIFACT_ID);
        String version = root.childTextTrimmed(MavenPomElements.Elements.VERSION);

        .onClose(streamB::close);
  }

  /**
   * Invokes {@code consumer} once for each pair of <i>corresponding</i> elements in {@code streamA}
   * and {@code streamB}. If one stream is longer than the other, the extra elements are silently
   * ignored. Elements passed to the consumer are guaranteed to come from the same position in their
   * respective source streams. For example:
   *
   * {@snippet :

        throw PermittedMetaException.ISE;
      }
    }

    private List<E> getElements() {
      List<E> elements = new ArrayList<>();
      Helpers.addAll(elements, previousElements);
      Helpers.addAll(elements, Helpers.reverse(nextElements));
      return elements;
    }
  }

  public enum KnownOrder {
    KNOWN_ORDER,
    UNKNOWN_ORDER
  }

   * @since 3.0
   */
  // TODO(kevinb): rerun benchmarks including new options
  public <E extends @NonNull T> ImmutableList<E> immutableSortedCopy(Iterable<E> elements) {
    return ImmutableList.sortedCopyOf(this, elements);
  }

  /**
   * Returns {@code true} if each element in {@code iterable} after the first is greater than or

        transaction.setParameterBytesWritten(200);
        transaction.setDataBytesWritten(300);

        // First element
        transaction.nextElement();
        assertTrue(transaction.hasMoreElements(), "Should have more elements for large data");

        // Process multiple elements
        int count = 1;
        while (transaction.hasMoreElements() && count < 10) {
            transaction.nextElement();

        .onClose(streamB::close);
  }

  /**
   * Invokes {@code consumer} once for each pair of <i>corresponding</i> elements in {@code streamA}
   * and {@code streamB}. If one stream is longer than the other, the extra elements are silently
   * ignored. Elements passed to the consumer are guaranteed to come from the same position in their
   * respective source streams. For example:
   *
   * {@snippet :

/**
 * Creates sorted sets, containing sample elements, to be tested.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public interface TestSortedSetGenerator<E extends @Nullable Object> extends TestSetGenerator<E> {
  @Override
  SortedSet<E> create(Object... elements);

  /**
   * Returns an element less than the {@link #samples()} and less than {@link
   * #belowSamplesGreater()}.