/** 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]. */
  val bufferMaxSize: Long,
) {
  /** The thread that currently has access to upstream. Possibly null. Guarded by this. */
  var upstreamReader: Thread? = null

  /**

   * chosen. Guarded by this.
   */
  internal var routeFailureCount = 0

  private var successCount = 0
  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

    )
  }

  /**
   * Returns a request that creates a TLS tunnel via an HTTP proxy. Everything in the tunnel request
   * is sent unencrypted to the proxy server, so tunnels include only the minimum set of headers.
   * This avoids sending potentially sensitive data like HTTP cookies to the proxy unencrypted.
   *
   * In order to support preemptive authentication we pass a fake "Auth Failed" response to the

  /** Web socket close timeout (in milliseconds). */
  @get:JvmName("webSocketCloseTimeout")
  val webSocketCloseTimeout: Int = builder.webSocketCloseTimeout

  /**
   * Minimum outbound web socket message size (in bytes) that will be compressed.
   * The default is 1024 bytes.
   */
  @get:JvmName("minWebSocketMessageToCompress")

   * If not, we create one and then schedule the task to run again immediately.
   */
  private fun openConnections(state: AddressState): Long {
    // This policy does not require minimum connections, don't run again
    if (state.policy.minimumConcurrentCalls == 0) return -1L

    var concurrentCallCapacity = 0
    for (connection in connections) {

    private val ONLY_HTTP1 = listOf(Protocol.HTTP_1_1)

    /**
     * The maximum number of bytes to enqueue. Rather than enqueueing beyond this limit we tear down
     * the web socket! It's possible that we're writing faster than the peer can read.
     */
    private const val MAX_QUEUE_SIZE = 16L * 1024 * 1024 // 16 MiB.

    /**
     * The maximum amount of time after the client calls [close] to wait for a graceful shutdown. If

 *  New: `HttpLoggingInterceptor.redactQueryParams()` configures the query parameters to redact
    in logs. For best security, don't put sensitive information in query parameters.

 *  New: `ConnectionPool.setPolicy()` configures a minimum connection pool size for a target
    address. Use this to proactively open HTTP connections.

    Connections opened to fulfill this policy are subject to the connection pool's

    const val HEADER_TABLE_SIZE = 1

    /** HTTP/2: The peer must not send a PUSH_PROMISE frame when this is 0. */
    const val ENABLE_PUSH = 2

    /** Sender's maximum number of concurrent streams. */
    const val MAX_CONCURRENT_STREAMS = 4

    /** HTTP/2: Size in bytes of the largest frame payload the sender will accept. */
    const val MAX_FRAME_SIZE = 5

 * }
 * ```
 *
 * This technique works even better in situations where a stale response is better than no response.
 * To permit stale cached responses, use the `max-stale` directive with the maximum staleness in
 * seconds:
 *
 * ```java
 * Request request = new Request.Builder()
 *     .cacheControl(new CacheControl.Builder()
 *         .maxStale(365, TimeUnit.DAYS)
 *         .build())

  internal const val OPCODE_CONTROL_PING = 0x9
  internal const val OPCODE_CONTROL_PONG = 0xa

  /**
   * Maximum length of frame payload. Larger payloads, if supported by the frame type, can use the
   * special values [PAYLOAD_SHORT] or [PAYLOAD_LONG].
   */
  internal const val PAYLOAD_BYTE_MAX = 125L

  /** Maximum length of close message in bytes. */
  internal const val CLOSE_MESSAGE_MAX = PAYLOAD_BYTE_MAX - 2

  /**