private var refusedStreamCount = 0

  /**
   * The maximum number of concurrent streams that can be carried by this connection. If
   * `allocations.size() < allocationLimit` then new streams can be created on this connection.
   */
  internal var allocationLimit = 1
    private set

  /** Current calls carried by this connection. */
  val calls = mutableListOf<Reference<RealCall>>()

   * [WindowCounter] generally carries the client view of total and acked bytes.
   */
  fun receivingStreamWindowChanged(
    streamId: Int,
    windowCounter: WindowCounter,
    bufferSize: Long,
  )

  /**
   * Notification that the receiving connection flow control window has changed.
   * [WindowCounter] generally carries the client view of total and acked bytes.
   */

 */
class Http1ExchangeCodec(
  /** The client that configures this stream. May be null for HTTPS proxy tunnels. */
  private val client: OkHttpClient?,
  override val carrier: ExchangeCodec.Carrier,
  private val source: BufferedSource,
  private val sink: BufferedSink,
) : ExchangeCodec {
  private var state = STATE_IDLE
  private val headersReader = HeadersReader(source)

 * **Exchange** carries a single HTTP request/response pair.

 * **ExchangeFinder** chooses which connection carries each exchange. Where possible it will use the same connection for all exchanges in a single call. It prefers reusing pooled connections over establishing new connections.      

   * the inbound request was truncated, this exception will be non-null.
   */
  val failure: IOException? = null,
) {
  val method: String?
  val path: String?

  /**
   * The TLS handshake of the connection that carried this request, or null if the request was
   * received without TLS.
   */
  val handshake: Handshake?
  val requestUrl: HttpUrl?

  /**

  internal val routes: List<Route>?,
  private val attempt: Int,
  private val tunnelRequest: Request?,
  internal val connectionSpecIndex: Int,
  internal val isTlsFallback: Boolean,
) : RoutePlanner.Plan, ExchangeCodec.Carrier {
  /** True if this connect was canceled; typically because it lost a race. */
  @Volatile private var canceled = false

  // These properties are initialized by connect() and never reassigned.

  /** Returns the HTTP status message. */
  @get:JvmName("message") val message: String,
  /** Returns the HTTP status code. */
  @get:JvmName("code") val code: Int,
  /**
   * Returns the TLS handshake of the connection that carried this response, or null if the
   * response was received without TLS.
   */
  @get:JvmName("handshake") val handshake: Handshake?,
  /** Returns the HTTP headers. */
  @get:JvmName("headers") val headers: Headers,
  /**

 *    Note that the private key is not a part of the certificate!
 *
 *  * **A signature issued by another certificate's private key.** This mechanism allows a trusted
 *    third-party to endorse a certificate. Third parties should only endorse certificates once
 *    they've confirmed that the owner of the private key is also the owner of the certificate's
 *    other properties.
 *

 * limitations under the License.
 */
package okhttp3.internal.http2

import java.io.IOException

/** Thrown when an HTTP/2 stream is canceled without damage to the socket that carries it. */
class StreamResetException(
  @JvmField val errorCode: ErrorCode,

     */
    fun Response.varyHeaders(): Headers {
      // Use the request headers sent over the network, since that's what the response varies on.
      // Otherwise OkHttp-supplied headers like "Accept-Encoding: gzip" may be lost.
      val requestHeaders = networkResponse!!.request.headers
      val responseHeaders = headers