function validateAndGetRedeemFee(address , address _address, uint256 _tokens) public view returns (uint256) {
        uint256 _icoTimestamp = store.getSetting("icoTimestamp");
        uint256 _redemptionTimeout = store.getSetting("redemptionTimeout");
        uint256 _fee = _tokens * store.getSetting("redemptionFee") / store.getSetting("percentage");

        require((_redemptionTimeout <= 0) || (block.timestamp > _icoTimestamp + _redemptionTimeout));
        require(_tokens > 0);
        require((_tokens + _fee) >= 0);
        require(store.getBalance(_address) >= (_tokens + _fee));

        return _fee;
    }