getLogger("org.conscrypt").level = Level.INFO
        } else {
          if (showHttp2Frames) {
            val activeLogger = getLogger(Http2::class.java.name)
            activeLogger.level = Level.FINE
            handler.level = Level.FINE
            handler.formatter = MessageFormatter
            activeLogger.addHandler(handler)
          }

          if (sslDebug) {
            val activeLogger = getLogger("javax.net.ssl")

      "FINE: Q10000 scheduled after 100 µs: task",
      "FINE: Q10000 starting              : task",
      "FINE: Q10000 run again after  50 µs: task",
      "FINE: Q10000 finished run in   0 µs: task",
      "FINE: Q10000 starting              : task",
      "FINE: Q10000 run again after 150 µs: task",
      "FINE: Q10000 finished run in   0 µs: task",
      "FINE: Q10000 starting              : task",

  fun connectionPreface() {
    this.withLock {
      if (closed) throw IOException("closed")
      if (!client) return // Nothing to write; servers don't send connection headers!
      if (logger.isLoggable(FINE)) {
        logger.fine(format(">> CONNECTION ${CONNECTION_PREFACE.hex()}"))
      }
      sink.write(CONNECTION_PREFACE)
      sink.flush()
    }
  }

  /** Applies `peerSettings` and then sends a settings ACK. */

      if (increment == 0L) throw IOException("windowSizeIncrement was 0")
    } catch (e: Exception) {
      logger.fine(frameLog(true, streamId, length, TYPE_WINDOW_UPDATE, flags))
      throw e
    }
    if (logger.isLoggable(FINE)) {
      logger.fine(
        frameLogWindowUpdate(
          inbound = true,
          streamId = streamId,
          length = length,

        }
    }

    return result
  }

  @Throws(IOException::class)
  private fun readEmptyLine(source: BufferedSource) {
    val line = source.readUtf8LineStrict()
    check(line.isEmpty()) { "Expected empty but was: $line" }
  }

  override fun toString(): String = "MockWebServer[$portField]"

  @Throws(IOException::class)
  override fun close() = shutdown()

  task: Task,
  queue: TaskQueue,
  messageBlock: () -> String,
) {
  if (isLoggable(Level.FINE)) {
    log(task, queue, messageBlock())
  }
}

internal inline fun <T> Logger.logElapsed(
  task: Task,
  queue: TaskQueue,
  block: () -> T,
): T {
  var startNs = -1L
  val loggingEnabled = isLoggable(Level.FINE)
  if (loggingEnabled) {
    startNs = queue.taskRunner.backend.nanoTime()

The new type [KeepAliveConfig] permits fine-tuning the keep-alive
options for TCP connections, via a new [TCPConn.SetKeepAliveConfig]

    val logs = testLogHandler.takeAll()
    assertThat(countFrames(logs, "FINE: >> 0x00000000     8 PING          "))
      .isEqualTo(1)
    assertThat(countFrames(logs, "FINE: << 0x00000000     8 PING          "))
      .isEqualTo(1)
    assertThat(countFrames(logs, "FINE: >> 0x00000000     8 PING          ACK"))
      .isEqualTo(1)
    assertThat(countFrames(logs, "FINE: << 0x00000000     8 PING          ACK"))
      .isEqualTo(1)
  }

  fun enableHttp2() = enable(Http2::class)

  fun enableTaskRunner() = enable(TaskRunner::class)

  fun logHandler() =
    ConsoleHandler().apply {
      level = Level.FINE
      formatter =
        object : SimpleFormatter() {
          override fun format(record: LogRecord) = String.format("[%1\$tF %1\$tT] %2\$s %n", record.millis, record.message)
        }
    }

  fun enable(

    write/flush after response handler has returned.
```

```
λ git cherry-pick 4f3317effea38c203c358af9cb5ce3c0e4173976
```