val isResponseComplete: Boolean

  /** The socket that carries this exchange. */
  val socket: Socket

  /** Returns an output stream where the request body can be streamed. */
  @Throws(IOException::class)
  fun createRequestBody(
    request: Request,
    contentLength: Long,
  ): Sink

  /** This should update the HTTP engine's sentRequestMillis field. */

   * [closed][ResponseBody] and may be consumed only once.
   *
   * If this is a [cacheResponse], [networkResponse], or [priorResponse], the server's response body
   * is not available, and it is always an error to attempt read its streamed content. Reading from
   * [ResponseBody.source] always throws on such instances.
   *
   * It is safe and supported to call [ResponseBody.contentType] and [ResponseBody.contentLength] on
   * all instances of [ResponseBody].

 *   <li>Supports a copy-free {@link #subArray} view, so methods that accept this type don't need to
 *       add overloads that accept start and end indexes.
 *   <li>Can be streamed without "breaking the chain": {@code foo.getBarInts().stream()...}.
 *   <li>Access to all collection-based utilities via {@link #asList} (though at the cost of
 *       allocating garbage).
 * </ul>
 *

 *   <li>Supports a copy-free {@link #subArray} view, so methods that accept this type don't need to
 *       add overloads that accept start and end indexes.
 *   <li>Can be streamed without "breaking the chain": {@code foo.getBarLongs().stream()...}.
 *   <li>Access to all collection-based utilities via {@link #asList} (though at the cost of
 *       allocating garbage).
 * </ul>
 *

 *       tests.
 * </ul>
 */
@SuppressWarnings({
  // We call threadUnexpectedException, which does the right thing for errors.
  "AssertionFailureIgnored",
  // We're following the upstream naming to reduce diffs.
  "IdentifierName",
  "ConstantCaseForConstants",
})
@NullUnmarked
abstract class JSR166TestCase extends TestCase {

    backwards-incompatible API changes that may impact early adopters of this alpha API.

 *  New: `mockwebserver3.Stream` for duplex streams.

 *  New: `mockwebserver3.MockResponseBody` for streamed response bodies.

 *  New: `mockwebserver3.MockResponse` is now immutable, with a `Builder`.

 *  New: `mockwebserver3.RecordedRequest.handshakeServerNames` returns the SNI (Server Name