const val TYPE_RST_STREAM = 0x3
  const val TYPE_SETTINGS = 0x4
  const val TYPE_PUSH_PROMISE = 0x5
  const val TYPE_PING = 0x6
  const val TYPE_GOAWAY = 0x7
  const val TYPE_WINDOW_UPDATE = 0x8
  const val TYPE_CONTINUATION = 0x9

  const val FLAG_NONE = 0x0
  const val FLAG_ACK = 0x1 // Used for settings and ping.
  const val FLAG_END_STREAM = 0x1 // Used for headers and data.

import okhttp3.internal.ws.WebSocketProtocol.OPCODE_CONTINUATION
import okhttp3.internal.ws.WebSocketProtocol.OPCODE_CONTROL_CLOSE
import okhttp3.internal.ws.WebSocketProtocol.OPCODE_CONTROL_PING
import okhttp3.internal.ws.WebSocketProtocol.OPCODE_CONTROL_PONG
import okhttp3.internal.ws.WebSocketProtocol.OPCODE_FLAG_CONTROL
import okhttp3.internal.ws.WebSocketProtocol.OPCODE_TEXT

      this.type = Http2.TYPE_RST_STREAM
      this.streamId = streamId
      this.errorCode = errorCode
    }

    override fun ping(
      ack: Boolean,
      payload1: Int,
      payload2: Int,
    ) {
      check(type == -1)
      type = Http2.TYPE_PING
      this.ack = ack
      this.payload1 = payload1
      this.payload2 = payload2
    }

    override fun goAway(

    peer.sendFrame().ping(false, 2, 3)
    peer.acceptFrame() // PING
    peer.play()

    // Play it back.
    connect(peer)

    // Verify the peer received what was expected.
    val ping = peer.takeFrame()
    assertThat(ping.type).isEqualTo(Http2.TYPE_PING)
    assertThat(ping.streamId).isEqualTo(0)
    assertThat(ping.payload1).isEqualTo(2)
    assertThat(ping.payload2).isEqualTo(3)

    the request already contains an `Accept` header.

 *  Fix: Don't crash with a `NullPointerException` if a server sends a close while we're sending a
    ping. OkHttp had a race condition bug.


## Version 4.6.0

_2020-04-28_

 *  Fix: Follow HTTP 307 and 308 redirects on methods other than GET and POST. We're reluctant to

  private val maskCursor: Buffer.UnsafeCursor? = if (isClient) Buffer.UnsafeCursor() else null

  /** Send a ping with the supplied [payload]. */
  @Throws(IOException::class)
  fun writePing(payload: ByteString) {
    writeControlFrame(OPCODE_CONTROL_PING, payload)
  }

  /** Send a pong with the supplied [payload]. */
  @Throws(IOException::class)
  fun writePong(payload: ByteString) {

  }

  @Test
  fun flagOverlapOn0x1() {
    assertThat(frameLog(true, 0, 0, TYPE_SETTINGS, 0x1))
      .isEqualTo("<< 0x00000000     0 SETTINGS      ACK")
    assertThat(frameLog(true, 0, 8, TYPE_PING, 0x1))
      .isEqualTo("<< 0x00000000     8 PING          ACK")
    assertThat(frameLog(true, 3, 0, TYPE_HEADERS, 0x1))
      .isEqualTo("<< 0x00000003     0 HEADERS       END_STREAM")
    assertThat(frameLog(true, 3, 0, TYPE_DATA, 0x1))

    fail("")
  }

  override fun settings(
    clearPrevious: Boolean,
    settings: Settings,
  ) {
    fail("")
  }

  override fun ackSettings() {
    fail("")
  }

  override fun ping(
    ack: Boolean,
    payload1: Int,
    payload2: Int,
  ) {
    fail("")
  }

  override fun goAway(
    lastGoodStreamId: Int,
    errorCode: ErrorCode,
    debugData: ByteString,
  ) {

    }
  }

  @Test fun pingRoundTrip() {
    val expectedPayload1 = 7
    val expectedPayload2 = 8
    writeMedium(frame, 8) // length
    frame.writeByte(Http2.TYPE_PING)
    frame.writeByte(Http2.FLAG_ACK)
    frame.writeInt(0) // connection-level
    frame.writeInt(expectedPayload1)
    frame.writeInt(expectedPayload2)

    // Check writer sends the same bytes.

016D          ; valid                                  # 1.1  LATIN SMALL LETTER U WITH BREVE
016E          ; mapped                 ; 016F          # 1.1  LATIN CAPITAL LETTER U WITH RING ABOVE
016F          ; valid                                  # 1.1  LATIN SMALL LETTER U WITH RING ABOVE
0170          ; mapped                 ; 0171          # 1.1  LATIN CAPITAL LETTER U WITH DOUBLE ACUTE