SUBSET_VIEW,
  DESCENDING_VIEW,

  /**
   * For documenting collections that support no optional features, such as {@link
   * java.util.Collections#emptySet}
   */
  NONE;

  private final Set<Feature<? super Collection>> implied;

  CollectionFeature(Feature<? super Collection>... implied) {
    this.implied = copyToSet(implied);
  }

  @Override

import junit.framework.Assert;

/**
 * Extra assert methods for testing Escaper implementations.
 *
 * @author David Beaumont
 * @since 15.0
 */
@GwtCompatible
public final class EscaperAsserts {
  private EscaperAsserts() {}

  /**
   * Asserts that an escaper behaves correctly with respect to null inputs.
   *
   * @param escaper the non-null escaper to test
   */

   */
  @ParametricNullness
  @SuppressWarnings("nullness")
  static <T extends @Nullable Object> T uncheckedCastNullableTToT(@Nullable T t) {
    return t;
  }

  private NullnessCasts() {}

  // such as BoundedQueueExecutorService to allow extends but it would be nice to make it final to
  // avoid unintended usage.

  // The execution list to hold our listeners.
  private final ExecutionList executionList = new ExecutionList();

  /**
   * Creates a {@code ListenableFutureTask} that will upon running, execute the given {@code
   * Callable}.
   *
   * @param callable the callable task

  public static <E> Iterable<E> unmodifiableIterable(ImmutableCollection<E> iterable) {
    return checkNotNull(iterable);
  }

  private static final class UnmodifiableIterable<T extends @Nullable Object>
      extends FluentIterable<T> {
    private final Iterable<? extends T> iterable;

    private UnmodifiableIterable(Iterable<? extends T> iterable) {
      this.iterable = iterable;
    }

    @Override

  /**
   * The HTTP <a href="https://wicg.github.io/private-network-access/#headers">{@code
   * Access-Control-Allow-Private-Network}</a> header field name.
   *
   * @since 31.1
   */
  public static final String ACCESS_CONTROL_ALLOW_PRIVATE_NETWORK =
      "Access-Control-Allow-Private-Network";

  /** The HTTP {@code Access-Control-Allow-Credentials} header field name. */

  val ca: Boolean,
  /** The maximum number of intermediate CAs between this and leaf certificates. */
  val maxIntermediateCas: Long?,
)

/** A private key. Note that this class doesn't support attributes or an embedded public key. */
internal data class PrivateKeyInfo(
  // v1(0), v2(1).
  val version: Long,
  val algorithmIdentifier: AlgorithmIdentifier,

    require(c == '\t' || c in '\u0020'..'\u007e') {
      "Unexpected char 0x${c.charCode()} at $i in $name value" +
        (if (isSensitiveHeader(name)) "" else ": $value")
    }
  }
}

private fun Char.charCode() =
  code.toString(16).let {
    if (it.length < 2) {
      "0$it"
    } else {
      it
    }
  }

internal fun commonHeadersOf(vararg inputNamesAndValues: String): Headers {

   * comparator.
   */
  @Override
  public Collection<V> values() {
    return super.values();
  }

  @GwtIncompatible @J2ktIncompatible   private static final long serialVersionUID = 430848587173315748L;

    /** does the actual artifact for this metadata exists */
    protected boolean artifactExists = false;
    /** artifact URI */
    protected String artifactUri;

    /** error message  */
    private String error;

    // ------------------------------------------------------------------
    /**
     *
     */
    public ArtifactMetadata(String name) {
        if (name == null) {
            return;