function withdraw(
        uint256 assets,
        address receiver,
        address owner
    ) public nonReentrant syncFeeCheckpoint returns (uint256 shares) {
        if (receiver == address(0)) revert InvalidReceiver();

        shares = convertToShares(assets);
/// .... [skipped the code]
function convertToShares(uint256 assets) public view returns (uint256) {
        uint256 supply = totalSupply(); // Saves an extra SLOAD if totalSupply is non-zero.

        return
            supply == 0
                ? assets
                : assets.mulDiv(supply, totalAssets(), Math.Rounding.Down);
    }
assets = 99
return value = assets * supply / totalAssets()
return value = 99 * 10 / 1000
return value = 0
