    function calculateAuctionPriceMultiplier(
        uint256 auctionStartTimestamp,
        uint256 currentTimestamp
    ) external view override returns (uint256) {
        uint256 ticks = PRBMathUD60x18.div(
            currentTimestamp - auctionStartTimestamp,
            _tickLength
        );
        return _calculateAuctionPriceMultiplierByTicks(ticks);
    }

    function _calculateAuctionPriceMultiplierByTicks(uint256 ticks)
        internal
        view
        returns (uint256)
    {
        if (ticks < PRBMath.SCALE) {
            return _maxPriceMultiplier;
        }

        uint256 ticksMinExp = PRBMathUD60x18.div(
            (PRBMathUD60x18.ln(_maxPriceMultiplier) -
                PRBMathUD60x18.ln(_minExpPriceMultiplier)),
            _stepExp
        );
        if (ticks <= ticksMinExp) {
            return
                PRBMathUD60x18.div(
                    _maxPriceMultiplier,
                    PRBMathUD60x18.exp(_stepExp.mul(ticks))
                );
        }

        uint256 priceMinExpEffective = PRBMathUD60x18.div(
            _maxPriceMultiplier,
            PRBMathUD60x18.exp(_stepExp.mul(ticksMinExp))
        );
        uint256 ticksMin = ticksMinExp +
            (priceMinExpEffective - _minPriceMultiplier).div(_stepLinear);

        if (ticks <= ticksMin) {
            return priceMinExpEffective - _stepLinear.mul(ticks - ticksMinExp);
        }

        return _minPriceMultiplier;
    }
    function isAuctioned(
        MintableERC721Data storage erc721Data,
        IPool POOL,
        uint256 tokenId
    ) public view returns (bool) {
        return
            erc721Data.auctions[tokenId].startTime >
            POOL
                .getUserConfiguration(erc721Data.owners[tokenId])
                .auctionValidityTime;
    }
