Comparator<? super E> comparator, Collection<? extends E> elements) {
    return copyOf(comparator, (Iterable<? extends E>) elements);
  }

  /**
   * Returns an immutable sorted set containing the elements of a sorted set, sorted by the same
   * {@code Comparator}. That behavior differs from {@link #copyOf(Iterable)}, which always uses the
   * natural ordering of the elements.
   *

   * writeLines(lines, System.getProperty("line.separator"))}.
   *
   * @throws IOException if an I/O error occurs while writing to this sink
   */
  public void writeLines(Iterable<? extends CharSequence> lines) throws IOException {
    writeLines(lines, System.getProperty("line.separator"));
  }

  /**

import com.google.common.collect.ListMultimap;
import com.google.common.collect.testing.features.MapFeature;
import java.util.List;
import org.junit.Ignore;

/**
 * Testers for {@link ListMultimap#replaceValues(Object, Iterable)}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore("test runners must not instantiate and run this directly, only via suites we build")

   * functions together: {@code Hashing.concatenating(Hashing.sha512(), Hashing.sha512())}.
   *
   * @since 19.0
   */
  public static HashFunction concatenating(Iterable<HashFunction> hashFunctions) {
    checkNotNull(hashFunctions);
    // We can't use Iterables.toArray() here because there's no hash->collect dependency
    List<HashFunction> list = new ArrayList<>();
    for (HashFunction hashFunction : hashFunctions) {

    list.add("a");
    try {
      assertEmpty(list);
      throw new Error();
    } catch (AssertionFailedError expected) {
    }
    try {
      assertEmpty(
          new Iterable<String>() {
            @Override
            public Iterator<String> iterator() {
              return singleton("a").iterator();
            }
          });
      throw new Error();

/**
 * A container class for the five sample elements we need for testing.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public class SampleElements<E extends @Nullable Object> implements Iterable<E> {
  // TODO: rename e3, e4 => missing1, missing2
  private final E e0;
  private final E e1;
  private final E e2;
  private final E e3;
  private final E e4;

    list.add("a");
    try {
      assertEmpty(list);
      throw new Error();
    } catch (AssertionFailedError expected) {
    }
    try {
      assertEmpty(
          new Iterable<String>() {
            @Override
            public Iterator<String> iterator() {
              return singleton("a").iterator();
            }
          });
      throw new Error();

    @SuppressWarnings("unchecked")
    @Override
    public Entry<String, Integer>[] createArray(int length) {
      return (Entry<String, Integer>[]) new Entry<?, ?>[length];
    }

    @Override
    public Iterable<Entry<String, Integer>> order(List<Entry<String, Integer>> insertionOrder) {
      return new Ordering<Entry<String, Integer>>() {
        @Override

              @Override
              public E[] createArray(int length) {
                return delegate.createArray(length);
              }

              @Override
              public Iterable<E> order(List<E> insertionOrder) {
                List<E> list = new ArrayList<>();
                for (E e : delegate.order(insertionOrder)) {
                  list.add(e);
                }

  }

  // TODO(cpovirk): should we reject null items, since the tests already check null automatically?
  @CanIgnoreReturnValue
  public RelationshipTester<T> addRelatedGroup(Iterable<? extends T> group) {
    groups.add(ImmutableList.copyOf(group));
    return this;
  }

  public void test() {
    for (int groupNumber = 0; groupNumber < groups.size(); groupNumber++) {