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

            ),
          )
        assertContent("B", response)
        break
      } catch (socketException: IOException) {
        // If there's a socket exception, this must have a streamed request body.
        assertThat(j).isEqualTo(0)
        assertThat(transferKind).isIn(TransferKind.CHUNKED, TransferKind.FIXED_LENGTH)
      }
    }
    val requestA = server.takeRequest()

        logger.fine(
          frameLogWindowUpdate(
            inbound = false,
            streamId = streamId,
            length = 4,
            windowSizeIncrement = windowSizeIncrement,
          ),
        )
      }
      frameHeader(
        streamId = streamId,
        length = 4,
        type = TYPE_WINDOW_UPDATE,
        flags = FLAG_NONE,
      )

    streamId: Int,
    requestHeaders: List<Header>,
  ) {
    this.withLock {
      if (streamId in currentPushRequests) {
        writeSynResetLater(streamId, ErrorCode.PROTOCOL_ERROR)
        return
      }
      currentPushRequests.add(streamId)
    }
    pushQueue.execute("$connectionName[$streamId] onRequest") {
      val cancel = pushObserver.onRequest(streamId, requestHeaders)
      ignoreIoExceptions {

      inFinished: Boolean,
      streamId: Int,
      source: BufferedSource,
      length: Int,
    ) {
      check(type == -1)
      this.type = Http2.TYPE_DATA
      this.inFinished = inFinished
      this.streamId = streamId
      this.data = source.readByteString(length.toLong()).toByteArray()
    }

    override fun rstStream(
      streamId: Int,
      errorCode: ErrorCode,
    ) {

interface PushObserver {
  /**
   * Describes the request that the server intends to push a response for.
   *
   * @param streamId server-initiated stream ID: an even number.
   * @param requestHeaders minimally includes `:method`, `:scheme`, `:authority`,
   * and `:path`.
   */
  fun onRequest(
    streamId: Int,
    requestHeaders: List<Header>,
  ): Boolean

  /**

      TYPE_DATA -> readData(handler, length, flags, streamId)
      TYPE_HEADERS -> readHeaders(handler, length, flags, streamId)
      TYPE_PRIORITY -> readPriority(handler, length, flags, streamId)
      TYPE_RST_STREAM -> readRstStream(handler, length, flags, streamId)
      TYPE_SETTINGS -> readSettings(handler, length, flags, streamId)
      TYPE_PUSH_PROMISE -> readPushPromise(handler, length, flags, streamId)

    check(acknowledged >= 0)

    this.total += total
    this.acknowledged += acknowledged

    check(this.acknowledged <= this.total)
  }

  override fun toString(): String {
    return "WindowCounter(streamId=$streamId, total=$total, acknowledged=$acknowledged, unacknowledged=$unacknowledged)"
  }

  override fun data(
    inFinished: Boolean,
    streamId: Int,
    source: BufferedSource,
    length: Int,
  ) {
    fail("")
  }

  override fun headers(
    inFinished: Boolean,
    streamId: Int,
    associatedStreamId: Int,
    headerBlock: List<Header>,
  ) {
    fail("")
  }

  override fun rstStream(
    streamId: Int,
    errorCode: ErrorCode,
  ) {
    fail("")
  }

  }

  @Test fun streamIdHasReservedBit() {
    val writer = Http2Writer(Buffer(), true)
    assertFailsWith<IllegalArgumentException> {
      var streamId = 3
      streamId = streamId or (1L shl 31).toInt() // set reserved bit
      writer.frameHeader(streamId, Http2.INITIAL_MAX_FRAME_SIZE, Http2.TYPE_DATA, FLAG_NONE)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("reserved bit set: -2147483645")
    }