Using a Bitcoin-Qt v0.16.0 ([downloaded from bitcoin page](https://bitcoin.org/bin/bitcoin-core-0.16.0/bitcoin-0.16.0-osx.dmg)) in an macOS High Sierra 10.13.4 

When I start after a fresh install Bitcoin-Qt as a mainnet node and wallet, the wallet prompt that about 203gb is going to be used in my disk
![image](https://user-images.githubusercontent.com/20187136/39899688-ba820bfe-5493-11e8-87d9-460ed5716a02.png)

When I start the node and wallet as testnet, shows the same message about the 203gb disk usage
![image](https://user-images.githubusercontent.com/20187136/39899756-17b31214-5494-11e8-8a57-60e604e74afb.png)

It seems that the second time the message is wrong, due that the testnet database uses about 14gb.
virtual CFeeRate estimateSmartFee(int num_blocks, bool conservative, int* returned_target = nullptr) = 0;
    
    virtual CFeeRate getDustRelayFee() = 0;
    
    virtual UniValue executeRpc(const std::string& command, const UniValue& params, const std::string& uri) = 0;
    
    virtual std::vector<std::string> listRpcCommands() = 0;
    
    virtual void rpcSetTimerInterfaceIfUnset(RPCTimerInterface* iface) = 0;
    
    virtual void rpcUnsetTimerInterface(RPCTimerInterface* iface) = 0;
    
    virtual bool getUnspentOutput(const COutPoint& output, Coin& coin) = 0;
    
    virtual std::vector<std::unique_ptr<Wallet>> getWallets() = 0;
    
    using InitMessageFn = std::function<void(const std::string& message)>;
    virtual std::unique_ptr<Handler> handleInitMessage(InitMessageFn fn) = 0;
    
    using MessageBoxFn =
        std::function<bool(const std::string& message, const std::string& caption, unsigned int style)>;
    virtual std::unique_ptr<Handler> handleMessageBox(MessageBoxFn fn) = 0;
    
    using QuestionFn = std::function<bool(const std::string& message,
        const std::string& non_interactive_message,
        const std::string& caption,
        unsigned int style)>;
    virtual std::unique_ptr<Handler> handleQuestion(QuestionFn fn) = 0;