if (_force && sponsorAmount > totalUnderlying()) {
    sponsorToTransfer = totalUnderlying();
} else if (!_force) {
    require(
        sponsorToTransfer <= totalUnderlying(),
        "Vault: not enough funds to unsponsor"
    );
}

totalSponsored -= sponsorAmount;

underlying.safeTransfer(_to, sponsorToTransfer);
