opcode = b0 and B0_MASK_OPCODE
    isFinalFrame = b0 and B0_FLAG_FIN != 0
    isControlFrame = b0 and OPCODE_FLAG_CONTROL != 0

    // Control frames must be final frames (cannot contain continuations).
    if (isControlFrame && !isFinalFrame) {
      throw ProtocolException("Control frames must be final.")
    }

    val reservedFlag1 = b0 and B0_FLAG_RSV1 != 0
    when (opcode) {
      OPCODE_TEXT, OPCODE_BINARY -> {

import okio.Buffer
import okio.BufferedSource
import okio.ByteString
import okio.Source
import okio.Timeout

/**
 * Reads HTTP/2 transport frames.
 *
 * This implementation assumes we do not send an increased [frame][Settings.getMaxFrameSize] to the
 * peer. Hence, we expect all frames to have a max length of [Http2.INITIAL_MAX_FRAME_SIZE].
 */
class Http2Reader(
  /** Creates a frame reader with max header table size of 4096. */

   */
  private fun doReadTimeout() = !connection.client || sink.closed || sink.finished

  /**
   * A source that reads the incoming data frames of a stream. Although this class uses
   * synchronization to safely receive incoming data frames, it is not intended for use by multiple
   * readers.
   */
  inner class FramingSource internal constructor(

  }

  @Test
  fun clientCloseCancelsConnectionAfterTimeout() {
    client.webSocket!!.close(1000, "Hello!")
    taskFaker.runTasks()
    // Note: we don't process server frames so our client 'close' doesn't receive a server 'close'.
    assertThat(client.canceled).isFalse()

    taskFaker.advanceUntil(ns(RealWebSocket.CANCEL_AFTER_CLOSE_MILLIS - 1))
    assertThat(client.canceled).isFalse()

  /** Outgoing messages and close frames in the order they should be written. */
  private val messageAndCloseQueue = ArrayDeque<Any>()

  /** The total size in bytes of enqueued but not yet transmitted messages. */
  private var queueSize = 0L

  /** True if we've enqueued a close frame. No further message frames will be enqueued. */
  private var enqueuedClose = false

    close(ErrorCode.PROTOCOL_ERROR, ErrorCode.PROTOCOL_ERROR, e)
  }

  /**
   * Sends any initial frames and starts reading frames from the remote peer. This should be called
   * after [Builder.build] for all new connections.
   *
   * @param sendConnectionPreface true to send connection preface frames. This should always be true
   *     except for in tests that don't check for a connection preface.

  /**
   * HTTP/2 only. Send a push promise header block.
   *
   * A push promise contains all the headers that pertain to a server-initiated request, and a
   * `promisedStreamId` to which response frames will be delivered. Push promise frames are sent as
   * a part of the response to `streamId`. The `promisedStreamId` has a priority of one greater than
   * `streamId`.
   *
   * @param streamId client-initiated stream ID.  Must be an odd number.

 *  Fix: MockWebServer explicitly closes sockets. (On some Android releases,
    closing the input stream and output stream of a socket is not sufficient.
 *  Fix: Buffer outgoing HTTP/2 frames to limit how many outgoing frames are
    created.
 *  Fix: Avoid crashing when cache writing fails due to a full disk.
 *  Fix: Improve caching of private responses.
 *  Fix: Update cache-by-default response codes.

pkg reflect, func StructOf([]StructField) Type
pkg reflect, method (StructTag) Lookup(string) (string, bool)
pkg runtime, func CallersFrames([]uintptr) *Frames
pkg runtime, func KeepAlive(interface{})
pkg runtime, func SetCgoTraceback(int, unsafe.Pointer, unsafe.Pointer, unsafe.Pointer)
pkg runtime, method (*Frames) Next() (Frame, bool)
pkg runtime, type Frame struct
pkg runtime, type Frame struct, Entry uintptr
pkg runtime, type Frame struct, File string

      assertThat(expected.message)
        .isEqualTo("Client-sent frames must be masked.")
    }
  }

  @Test fun serverSentFramesMustNotBeMasked() {
    data.write("8180".decodeHex())
    assertFailsWith<ProtocolException> {
      clientReader.processNextFrame()
    }.also { expected ->
      assertThat(expected.message)
        .isEqualTo("Server-sent frames must not be masked.")
    }
  }