https://github.com/bitcoin/bitcoin/commit/2b781ad66e34000037f589c71366c203255ed058#r83655059
{
    auto sock = CreateSock(m_control_host);
    if (!sock) {
        throw std::runtime_error("Cannot create socket");
    }
    if (!ConnectSocketDirectly(m_control_host, *sock, nConnectTimeout, true)) {
        throw std::runtime_error(strprintf("Cannot connect to %s", m_control_host.ToString()));
    }
    SendRequestAndGetReply(*sock, "HELLO VERSION MIN=3.1 MAX=3.1");
    return sock;
}
void Session::CheckControlSock()