*/
  internal var allocationLimit = 1
    private set

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

  /** Timestamp when `allocations.size()` reached zero. Also assigned upon initial connection. */
  var idleAtNs = Long.MAX_VALUE

  /**
   * Returns true if this is an HTTP/2 connection. Such connections can be used in multiple HTTP

  /**
   * Returns a [timestamp][System.currentTimeMillis] taken immediately before OkHttp
   * transmitted the initiating request over the network. If this response is being served from the
   * cache then this is the timestamp of the original request.
   */
  @get:JvmName("sentRequestAtMillis") val sentRequestAtMillis: Long,
  /**
   * Returns a [timestamp][System.currentTimeMillis] taken immediately after OkHttp

          override fun encode(
            writer: DerWriter,
            value: String,
          ) = writer.writeUtf8(value)
        },
    )

  /**
   * A timestamp like "191216030210Z" or "191215190210-0800" for 2019-12-15T19:02:10-08:00. The
   * cutoff of the 2-digit year is 1950-01-01T00:00:00Z.
   */
  val UTC_TIME =
    BasicDerAdapter(
      name = "UTC TIME",

     */
    private var expires: Date? = null

    /**
     * Extension header set by OkHttp specifying the timestamp when the cached HTTP request was
     * first initiated.
     */
    private var sentRequestMillis = 0L

    /**
     * Extension header set by OkHttp specifying the timestamp when the cached HTTP response was
     * first received.
     */
    private var receivedResponseMillis = 0L