        uint256 balanceBefore = IERC20(asset()).balanceOf(receiver);


        if (msg.sender != owner) {
            _spendAllowance(owner, msg.sender, shares);
        }
        _redeemInternal(shares, receiver, owner);
/////////////
Control is transferred to user. They can alter their balance here.
///////////

        uint256 balanceAfter = IERC20(asset()).balanceOf(receiver);
        uint256 assets = balanceAfter - balanceBefore;

//////////
Assets can be as low as 0 if they have transferred the same amount out as received.
//////////

        emit Withdraw(msg.sender, receiver, owner, assets, shares);
        return assets;
