private fun timeoutExit(cause: IOException?): IOException? {
    if (timeoutEarlyExit) return cause
    if (!timeout.exit()) return cause

    val e = InterruptedIOException("timeout")
    if (cause != null) e.initCause(cause)
    return e
  }

  /**
   * Stops applying the timeout before the call is entirely complete. This is used for WebSockets
   * and duplex calls where the timeout only applies to the initial setup.
   */