private fun cancelDuringConnect(scheme: String?) {
    server.enqueue(MockResponse.Builder().onRequestStart(Stall).build())
    val cancelDelayMillis = 300L
    val call =
      client.newCall(
        Request(
          server
            .url("/")
            .newBuilder()
            .scheme(scheme!!)
            .build(),
        ),
      )

    public static final String LABELS_NUM = "{labels.num}";

    /** The key of the message: Page Number */
    public static final String LABELS_PN = "{labels.pn}";

    /** The key of the message: Scheme */
    public static final String LABELS_PROTOCOL_SCHEME = "{labels.protocolScheme}";

    /** The key of the message: Purge Bots */
    public static final String LABELS_PURGE_BY_BOTS = "{labels.purgeByBots}";

    assertThat(call).contains("prompt=Bar")
    assertThat(call).contains("protocol=http")
    assertThat(call.lowercase(Locale.US))
      .contains("scheme=basic") // lowercase for the RI.
  }

  @Test
  fun allAttributesSetInProxyAuthenticationCallbacks() {
    val calls = authCallsForHeader("Proxy-Authenticate: Basic realm=\"Bar\"")