function withdrawFunds(address beneficiary, uint withdrawAmount) external onlyOwner {
        require (withdrawAmount <= address(this).balance);

        uint safetyAmount = jackpotSize.add(lockedInBets).add(withdrawAmount);
        safetyAmount = safetyAmount.add(withdrawAmount);

        require (safetyAmount <= address(this).balance);
        sendFunds(beneficiary, withdrawAmount, withdrawAmount);
    }