* proceed to read the response body with [Response.body]. The response is still live until its
   * response body is [closed][ResponseBody]. The recipient of the callback may consume the response
   * body on another thread.
   *
   * Note that transport-layer success (receiving a HTTP response code, headers and body) does not

    // appendCodePoint(). The Punycode algorithm processes code points in increasing code-point
    // order, not in increasing index order.
    val codePoints = mutableListOf<Int>()

    // consume all code points before the last delimiter (if there is one)
    //  and copy them to output, fail on any non-basic code point
    val lastDelimiter = string.lastIndexOf('-', limit)
    if (lastDelimiter >= pos) {

  fun matches(header: DerHeader): Boolean

  /**
   * Returns a value from this adapter.
   *
   * This must always return a value, though it doesn't necessarily need to consume data from
   * [reader]. For example, if the reader's peeked tag isn't readable by this adapter, it may return
   * a default value.
   *

      result.write(this, i)
      // Consume '"'.
      readByte()
      return result.readUtf8()
    }

    if (size == i + 1L) return null // Dangling escape.
    result.write(this, i)
    // Consume '\'.
    readByte()
    result.write(this, 1L) // The escaped character.
  }
}

/**
 * Consumes and returns a non-empty token, terminating at special characters in

      if (pos == value.length || value[pos] == ',' || value[pos] == ';') {
        pos++ // Consume ',' or ';' (if necessary).
        parameter = null
      } else {
        pos++ // Consume '='.
        pos = value.indexOfNonWhitespace(pos)

        if (pos < value.length && value[pos] == '\"') {
          // Quoted string.
          pos++ // Consume '"' open quote.
          val parameterStart = pos

    // Note that this may be be an encoded "end of data" header.
    return DerHeader(tagClass, tag, constructed, length)
  }

  /**
   * Consume a header and execute [block], which should consume the entire value described by the
   * header. It is an error to not consume a full value in [block].
   */
  internal inline fun <T> read(
    name: String?,
    block: (DerHeader) -> T,
  ): T {

      // Read a boundary, skipping the remainder of the preceding part as necessary.
      if (partCount == 0 && source.rangeEquals(0L, dashDashBoundary)) {
        // This is the first part. Consume "--" followed by the boundary.
        source.skip(dashDashBoundary.size.toLong())
      } else {
        // This is a subsequent part or a preamble. Skip until "\r\n--" followed by the boundary.
        while (true) {

    timeout.setDelegate(Timeout.NONE)
    oldDelegate.clearDeadline()
    oldDelegate.clearTimeout()
  }

  /**
   * The response body from a CONNECT should be empty, but if it is not then we should consume it
   * before proceeding.
   */
  fun skipConnectBody(response: Response) {
    val contentLength = response.headersContentLength()
    if (contentLength == -1L) return

  /**
   * Null once the file has a complete copy of the upstream bytes. Only the [upstreamReader] thread
   * may access this source.
   */
  var upstream: Source?,
  /** The number of bytes consumed from [upstream]. Guarded by this. */
  var upstreamPos: Long,
  /** User-supplied additional data persisted with the source data. */
  private val metadata: ByteString,
  /** The maximum size of [buffer]. */

 *
 * Instances of [HttpUrl] are well-formed and always have a scheme, host, and path. With
 * `java.net.URL` it's possible to create an awkward URL like `http:/` with scheme and path but no
 * hostname. Building APIs that consume such malformed values is difficult!
 *
 * This class has a modern API. It avoids punitive checked exceptions: [toHttpUrl] throws
 * [IllegalArgumentException] on invalid input or [toHttpUrlOrNull] returns null if the input is an