* most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)
    val source: Source =
      object : Source {
        var closed = false

        override fun close() {
          closed = true
        }

        override fun read(
          sink: Buffer,

class PostPath {
  private val client = OkHttpClient()
  private val fileSystem = FakeFileSystem()
  val path = "test.json".toPath()

  fun run() {
    fileSystem.write(path) {
      writeUtf8("{}")
    }

    val request =
      Request
        .Builder()
        .url("https://httpbin.org/anything")
        .put(path.asRequestBody(fileSystem, MEDIA_TYPE_JSON))
        .build()

  try {
    val certificateFactory = CertificateFactory.getInstance("X.509")
    val certificates =
      certificateFactory
        .generateCertificates(
          Buffer().writeUtf8(this).inputStream(),
        )

    return certificates.single() as X509Certificate
  } catch (nsee: NoSuchElementException) {
    throw IllegalArgumentException("failed to decode certificate", nsee)

          i++
        }

        list += element
      }
      return list
    }

    private fun unescape(s: String): String =
      buildString {
        val buffer = Buffer().writeUtf8(s)
        while (!buffer.exhausted()) {
          val c = buffer.readUtf8CodePoint()
          if (c != '\\'.code) {
            append(c.toChar())
            continue
          }

          val chunkSize = minOf(body.size, maxChunkSize.toLong())
          bytesOut.writeHexadecimalUnsignedLong(chunkSize)
          bytesOut.writeUtf8("\r\n")
          bytesOut.write(body, chunkSize)
          bytesOut.writeUtf8("\r\n")
        }
        bytesOut.writeUtf8("0\r\n") // Last chunk. Trailers follow!
        this.body = bytesOut.toMockResponseBody()
      }

    /**

        ) {
          callbacks.add(Event(id, type, data))
        }

        override fun onRetryChange(timeMs: Long) {
          callbacks.add(timeMs)
        }
      }
    val buffer = Buffer().writeUtf8(source)
    val reader = ServerSentEventReader(buffer, callback)
    while (reader.processNextEvent()) {
    }
    assertThat(buffer.size, "Unconsumed buffer: ${buffer.readUtf8()}")
      .isEqualTo(0)
  }

      }

    if (metadataFile != null) {
      val contents =
        fileSystem.read(metadataFile) {
          readUtf8()
        }

      fileSystem.write(metadataFile) {
        writeUtf8(corruptor(contents))
      }
    }
  }

  private fun testCorruptingCache(corruptor: () -> Unit): Response {
    server.useHttps(handshakeCertificates.sslSocketFactory())
    server.enqueue(

    vararg bodyLines: String,
  ) {
    filesystem.write(journalFile) {
      writeUtf8(
        """
        |$magic
        |$version
        |$appVersion
        |$valueCount
        |$blank
        |
        """.trimMargin(),
      )
      for (line in bodyLines) {
        writeUtf8(line)
        writeUtf8("\n")
      }
    }
  }

fun Headers.parseChallenges(headerName: String): List<Challenge> {
  val result = mutableListOf<Challenge>()
  for (h in 0 until size) {
    if (headerName.equals(name(h), ignoreCase = true)) {
      val header = Buffer().writeUtf8(value(h))
      try {
        header.readChallengeHeader(result)
      } catch (e: EOFException) {
        Platform.get().log("Unable to parse challenge", Platform.WARN, e)
      }
    }
  }
  return result
}

  if (result.containsInvalidLabelLengths()) return null

  return result
}

internal fun idnToAscii(host: String): String? {
  val bufferA = Buffer().writeUtf8(host)
  val bufferB = Buffer()

  // 1. Map, from bufferA to bufferB.
  while (!bufferA.exhausted()) {
    val codePoint = bufferA.readUtf8CodePoint()