writeMedium(frame, (headerBlock.size / 2).toInt() + paddingLength + 1)
    frame.writeByte(Http2.TYPE_HEADERS)
    frame.writeByte(FLAG_PADDED)
    frame.writeInt(expectedStreamId and 0x7fffffff)
    frame.writeByte(paddingLength)
    frame.write(headerBlock, headerBlock.size / 2)
    frame.write(padding)

    // Write the continuation frame, specifying no more frames are expected.

            return f1.isDirectory() ? -1 : 1;
        }
        f2name = f2.getName();
        if( f1.isDirectory() ) {
            return f1name.compareToIgnoreCase( f2name );
        }
        i = f1name.lastIndexOf( '.' );
        t1 = i == -1 ? "" : f1name.substring( i + 1 );
        i = f2name.lastIndexOf( '.' );
        t2 = i == -1 ? "" : f2name.substring( i + 1 );

        i = t1.compareToIgnoreCase( t2 );

      reason: String,
    )
  }

  /**
   * Process the next protocol frame.
   *
   *  * If it is a control frame this will result in a single call to [FrameCallback].
   *  * If it is a message frame this will result in a single call to [FrameCallback.onReadMessage].
   *    If the message spans multiple frames, each interleaved control frame will result in a
   *    corresponding call to [FrameCallback].
   */

            return f1.isDirectory() ? -1 : 1;
        }
        f2name = f2.getName();
        if ( f1.isDirectory() ) {
            return f1name.compareToIgnoreCase(f2name);
        }
        i = f1name.lastIndexOf('.');
        t1 = i == -1 ? "" : f1name.substring(i + 1);
        i = f2name.lastIndexOf('.');
        t2 = i == -1 ? "" : f2name.substring(i + 1);

        i = t1.compareToIgnoreCase(t2);

  ): Boolean {
    // Don't send new frames after we've failed or enqueued a close frame.
    if (failed || enqueuedClose) return false

    // If this frame overflows the buffer, reject it and close the web socket.
    if (queueSize + data.size > MAX_QUEUE_SIZE) {
      close(CLOSE_CLIENT_GOING_AWAY, null)
      return false
    }

    // Enqueue the message frame.
    queueSize += data.size.toLong()

        if (closed) return
        outFinished = errorCode == null
      }
      if (!sink.finished) {
        // We have 0 or more frames of data, and 0 or more frames of trailers. We need to send at
        // least one frame with the END_STREAM flag set. That must be the last frame, and the
        // trailers must be sent after all of the data.
        val hasData = sendBuffer.size > 0L
        val hasTrailers = trailers != null

    // Note: we don't process server frames so our client 'close' doesn't receive a server 'close'.
    assertThat(client.canceled).isFalse()

    taskFaker.advanceUntil(ns(4_999))
    assertThat(client.canceled).isFalse()

    taskFaker.advanceUntil(ns(5_000))
    assertThat(client.canceled).isTrue()

    client.processNextFrame() // This won't get a frame, but it will get a closed pipe.

    API. Requests made with OkUrlFactory will continue to have a default user
    agent.
 *  New: Guava-like API to create headers:

    ```java
    Headers headers = Headers.of(name1, value1, name2, value2, ...).
    ```

 *  New: Make the content-type header optional for request bodies.
 *  New: `Response.isSuccessful()` is a convenient API to check response codes.

    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.

      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.")
    }
  }