assertThat(attempt0.isTlsFallback).isFalse()
    connectionSpecs[attempt0.connectionSpecIndex].apply(socket, attempt0.isTlsFallback)
    assertEnabledProtocols(socket, TlsVersion.TLS_1_2)
    val attempt1 = attempt0.nextConnectionSpec(connectionSpecs, socket)
    assertThat(attempt1).isNotNull()
    assertThat(attempt1!!.isTlsFallback).isTrue()
    socket.close()

    // COMPATIBLE_TLS is used here.