SUPPORTS_REMOVE,
  /**
   * Support for {@link ListIterator#add(Object)}; ignored for plain {@link Iterator}
   * implementations.
   */
  SUPPORTS_ADD,
  /**
   * Support for {@link ListIterator#set(Object)}; ignored for plain {@link Iterator}
   * implementations.
   */
  SUPPORTS_SET;

  /**
   * A set containing none of the optional features of the {@link Iterator} or {@link ListIterator}
   * interfaces.
   */

 * [system DNS service][SYSTEM], which is the default. Some applications may provide their own
 * implementation to use a different DNS server, to prefer IPv6 addresses, to prefer IPv4 addresses,
 * or to force a specific known IP address.
 *
 * Implementations of this interface must be safe for concurrent use.
 */
fun interface Dns {
  /**

 * href="https://docs.oracle.com/javase/7/docs/api/java/util/ListIterator.html">before {@code
 * default} methods were introduced</a>. For newer methods, like {@code forEachRemaining}, it
 * inherits their default implementations. When those implementations invoke methods, they invoke
 * methods on the {@code ForwardingListIterator}.
 *
 * @author Mike Bostock
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

          .build();

  /**
   * type → implementation. Inherently mutable interfaces and abstract classes are mapped to their
   * default implementations and are "new"d upon get().
   */
  private static final ConcurrentMap<Class<?>, Class<?>> implementations = Maps.newConcurrentMap();

  private static <T> void setImplementation(Class<T> type, Class<? extends T> implementation) {

package okhttp3.internal.http2

import java.io.IOException
import okhttp3.Protocol
import okio.BufferedSource

/**
 * [HTTP/2][Protocol.HTTP_2] only. Processes server-initiated HTTP requests on the client.
 * Implementations must quickly dispatch callbacks to avoid creating a bottleneck.
 *
 * While [onReset] may occur at any time, the following callbacks are expected in order,
 * correlated by stream ID.
 *
 *  * [onRequest]

 * ```
 *
 * ## Reactive Authentication
 *
 * Implementations authenticate by returning a follow-up request that includes an authorization
 * header, or they may decline the challenge by returning null. In this case the unauthenticated
 * response will be returned to the caller that triggered it.
 *
 * Implementations should check if the initial request already included an attempt to

 * override {@code addAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardAddAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code
 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingList}.
 *

 * This extensible enum has two defined values, {@link #MAIN} and {@link #TEST},
 * but can be extended by registering a {@code org.apache.maven.api.spi.ProjectScopeProvider}.
 * <p>
 * Implementation must have {@code equals()} and {@code hashCode()} implemented, so implementations of this interface
 * can be used as keys.
 *
 * @since 4.0.0
 */
@Experimental
@Immutable
@SuppressWarnings("checkstyle:InterfaceIsType")

 * the License.
 */

/**
 * Interfaces, utilities, and simple implementations of escapers and encoders. The primary type is
 * {@link Escaper}.
 *
 * <p>Additional escapers implementations are found in the applicable packages: {@link
 * com.google.common.html.HtmlEscapers} in {@code com.google.common.html}, {@link

 *
 * As policy, implementations of this interface are responsible for selecting which cookies to
 * accept and which to reject. A reasonable policy is to reject all cookies, though that may
 * interfere with session-based authentication schemes that require cookies.
 *
 * As persistence, implementations of this interface must also provide storage of cookies. Simple