SocketTimeoutException::class.java,
      "sent ping but didn't receive pong within 500ms (after 0 successful ping/pongs)",
    )
  }

  @Test
  fun unexpectedPongsDoNotInterfereWithFailureDetection() {
    client.initWebSocket(random, pingIntervalMillis = 500)

    // At 0ms the server sends 3 unexpected pongs. The client accepts 'em and ignores em.
    server.webSocket!!.pong("pong 1".encodeUtf8())
    client.processNextFrame()

        .build(),
    )
    val webSocket = newWebSocket()
    clientListener.assertOpen()
    val server = serverListener.assertOpen() as RealWebSocket
    Thread.sleep(1000)

    // No pings and no pongs.
    assertThat(webSocket.sentPingCount()).isEqualTo(0)
    assertThat(webSocket.receivedPingCount()).isEqualTo(0)
    assertThat(webSocket.receivedPongCount()).isEqualTo(0)
    assertThat(server.sentPingCount()).isEqualTo(0)

    }
  }

  /**
   * Attempts to remove a single frame from a queue and send it. This prefers to write urgent pongs
   * before less urgent messages and close frames. For example it's possible that a caller will
   * enqueue messages followed by pongs, but this sends pongs followed by messages. Pongs are always
   * written in the order they were enqueued.
   *