function _xp(Swap storage self, uint256[] memory balances)
    internal
    view
    returns (uint256[] memory)
{
    return _xp(balances, self.tokenPrecisionMultipliers);
}
function _xp(Swap storage self, uint256[] memory balances)
    internal
    view
    returns (uint256[] memory)
{
    uint256[2] memory tokenPrecisionMultipliers = self.tokenPrecisionMultipliers;
    tokenPrecisionMultipliers[0] = self.targetPrice.originalPrecisionMultipliers[0].mul(_getTargetPricePrecise(self)).div(WEI_UNIT)
    return _xp(balances, tokenPrecisionMultipliers);
}
