import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/**
 * A mutable class-to-instance map backed by an arbitrary user-provided map. See also {@link
 * ImmutableClassToInstanceMap}.
 *
 * <p>See the Guava User Guide article on <a href=

  }

  private static <T extends @Nullable Object> List<T> shuffledCopy(List<T> in, Random random) {
    List<T> mutable = new ArrayList<>(in);
    List<T> out = new ArrayList<>();
    while (!mutable.isEmpty()) {
      out.add(mutable.remove(random.nextInt(mutable.size())));
    }
    return out;
  }

  }

  private static <T extends @Nullable Object> List<T> shuffledCopy(List<T> in, Random random) {
    List<T> mutable = new ArrayList<>(in);
    List<T> out = new ArrayList<>();
    while (!mutable.isEmpty()) {
      out.add(mutable.remove(random.nextInt(mutable.size())));
    }
    return out;
  }

    yStats.addAll(values.yStats());
  }

  /** Returns an immutable snapshot of the current statistics. */
  public PairedStats snapshot() {
    return new PairedStats(xStats.snapshot(), yStats.snapshot(), sumOfProductsOfDeltas);
  }

  /** Returns the number of pairs in the dataset. */
  public long count() {
    return xStats.count();
  }

  /** Returns an immutable snapshot of the statistics on the {@code x} values alone. */

   * that this method will return a different number of chars than would be returned by reading all
   * of the chars.
   *
   * <p>Additionally, for mutable sources such as {@code StringBuilder}s, a subsequent read may
   * return a different number of chars if the contents are changed.
   *
   * @since 19.0
   */
  public Optional<Long> lengthIfKnown() {

   * that this method will return a different number of chars than would be returned by reading all
   * of the chars.
   *
   * <p>Additionally, for mutable sources such as {@code StringBuilder}s, a subsequent read may
   * return a different number of chars if the contents are changed.
   *
   * @since 19.0
   */
  public Optional<Long> lengthIfKnown() {

  private lateinit var serverIpv6: MockWebServer

  private val eventRecorder = EventRecorder()
  private lateinit var client: OkHttpClient
  private lateinit var url: HttpUrl

  /**
   * This is mutable and order matters. By default, it contains [IPv4, IPv6]. Tests may manipulate
   * it to prefer IPv6.
   */
  private var dnsResults = listOf<InetAddress>()

  @BeforeEach
  internal fun setUp() {

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {
    return new CompactLinkedHashSet<>();
  }

  /**
   * Creates a <i>mutable</i> {@code CompactLinkedHashSet} instance containing the elements of the
   * given collection in the order returned by the collection's iterator.
   *
   * @param collection the elements that the set should contain

  /** Creates an empty {@code CompactLinkedHashSet} instance. */
  public static <E extends @Nullable Object> CompactLinkedHashSet<E> create() {
    return new CompactLinkedHashSet<>();
  }

  /**
   * Creates a <i>mutable</i> {@code CompactLinkedHashSet} instance containing the elements of the
   * given collection in the order returned by the collection's iterator.
   *
   * @param collection the elements that the set should contain

   *     helpful predefined constants
   * @return a mutable {@link List} containing all the lines
   * @throws IOException if an I/O error occurs
   */
  public static List<String> readLines(File file, Charset charset) throws IOException {
    // don't use asCharSource(file, charset).readLines() because that returns
    // an immutable list, which would change the behavior of this method