}
      return -1L
    }
  }

  companion object {
    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.

    /**