https://travis-ci.org/github/bitcoin/bitcoin/jobs/679885530#L8791
bool getUnspentOutput(const COutPoint& output, Coin& coin) override
    {
        LOCK(::cs_main);
        return ::ChainstateActive().CoinsTip().GetCoin(output, coin);
    }
    WalletClient& walletClient() override
    {
        return *Assert(m_context->wallet_client);
    }
    std::unique_ptr<Handler> handleInitMessage(InitMessageFn fn) override
    {
        return MakeHandler(::uiInterface.InitMessage_connect(fn));
    }
    std::unique_ptr<Handler> handleMessageBox(MessageBoxFn fn) override
    {
        return MakeHandler(::uiInterface.ThreadSafeMessageBox_connect(fn));
    }
    std::unique_ptr<Handler> handleQuestion(QuestionFn fn) override
    {
        return MakeHandler(::uiInterface.ThreadSafeQuestion_connect(fn));
    }
    std::unique_ptr<Handler> handleShowProgress(ShowProgressFn fn) override
    {
        return MakeHandler(::uiInterface.ShowProgress_connect(fn));
    }
    std::unique_ptr<Handler> handleNotifyNumConnectionsChanged(NotifyNumConnectionsChangedFn fn) override
    {
        return MakeHandler(::uiInterface.NotifyNumConnectionsChanged_connect(fn));
    }
    std::unique_ptr<Handler> handleNotifyNetworkActiveChanged(NotifyNetworkActiveChangedFn fn) override