fun writeData(
    streamId: Int,
    outFinished: Boolean,
    buffer: Buffer?,
    byteCount: Long,
  ) {
    // Empty data frames are not flow-controlled.
    if (byteCount == 0L) {
      writer.data(outFinished, streamId, buffer, 0)
      return
    }

    var byteCount = byteCount
    while (byteCount > 0L) {
      var toWrite: Int
      this.withLock {
        try {

class HeadersJvmTest {
  @Test fun byteCount() {
    assertThat(EMPTY_HEADERS.byteCount()).isEqualTo(0L)
    assertThat(
      Headers.Builder()
        .add("abc", "def")
        .build()
        .byteCount(),
    ).isEqualTo(10L)
    assertThat(
      Headers.Builder()
        .add("abc", "def")
        .add("ghi", "jkl")
        .build()
        .byteCount(),
    ).isEqualTo(20L)
  }

  private val bytesPerPeriod: Long,
  private val periodDelayNanos: Long,
) : Sink by delegate {
  private var bytesWrittenSinceLastDelay = 0L

  override fun write(
    source: Buffer,
    byteCount: Long,
  ) {
    var bytesLeft = byteCount

    while (bytesLeft > 0) {
      if (bytesWrittenSinceLastDelay == bytesPerPeriod) {
        flush()
        sleepNanos(periodDelayNanos)
        bytesWrittenSinceLastDelay = 0
      }

          imports = ["okhttp3.RequestBody.Companion.toRequestBody"],
        ),
      level = DeprecationLevel.WARNING,
    )
    fun create(
      contentType: MediaType?,
      content: ByteArray,
      offset: Int = 0,
      byteCount: Int = content.size,
    ): RequestBody = content.toRequestBody(contentType, offset, byteCount)

    @JvmStatic
    @Deprecated(

          val bytesToRead = minOf(byteCount, upstreamPos - sourcePos)
          buffer.copyTo(sink, sourcePos - bufferPos, bytesToRead)
          sourcePos += bytesToRead
          return bytesToRead
        }

      // Read from the file.
      if (source == SOURCE_FILE) {
        val bytesToRead = minOf(byteCount, upstreamPos - sourcePos)

    countBytes: Boolean,
  ): Long {
    var byteCount = 0L
    val buffer: Buffer = if (countBytes) Buffer() else sink!!.buffer

    for (i in 0 until encodedNames.size) {
      if (i > 0) buffer.writeByte('&'.code)
      buffer.writeUtf8(encodedNames[i])
      buffer.writeByte('='.code)
      buffer.writeUtf8(encodedValues[i])
    }

    if (countBytes) {
      byteCount = buffer.size
      buffer.clear()
    }

01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] responseBodyStart
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] responseBodyEnd: byteCount=128
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] connectionReleased
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] callEnd
01-01 12:53:32.816 10999 11090 D OkHttp  : [54 ms] responseHeadersStart

  inner class FaultySink(sink: Sink, private val file: Path) : ForwardingSink(sink) {
    override fun write(
      source: Buffer,
      byteCount: Long,
    ) {
      if (writeFaults.contains(file)) {
        throw IOException("boom!")
      } else {
        super.write(source, byteCount)
      }
    }
  }

 * sample of code points to detect unicode control characters commonly used in binary file
 * signatures.
 */
fun Buffer.isProbablyUtf8(): Boolean {
  try {
    val prefix = Buffer()
    val byteCount = size.coerceAtMost(64)
    copyTo(prefix, 0, byteCount)
    for (i in 0 until 16) {
      if (prefix.exhausted()) {
        break
      }
      val codePoint = prefix.readUtf8CodePoint()

        var closed = false

        override fun close() {
          closed = true
        }

        override fun read(
          sink: Buffer,
          byteCount: Long,
        ): Long {
          check(!closed)
          return data.read(sink, byteCount)
        }

        override fun timeout(): Timeout {
          return Timeout.NONE
        }
      }
    return source.buffer().asResponseBody(null, -1)
  }