uint256 _redemptionWeight = _redemptionWeightOf(_decodedTokenIds);
uint256 _total = _totalRedemptionWeight();
uint256 _base = PRBMath.mulDiv(_data.overflow, _redemptionWeight, _total);
for (uint256 _i; _i < _maxTierId; ) {
  // Keep a reference to the stored tier.
  _storedTier = _storedTierOf[_nft][_i + 1];
  // Add the tier's contribution floor multiplied by the quantity minted.
  weight +=
    (_storedTier.contributionFloor *
      (_storedTier.initialQuantity - _storedTier.remainingQuantity)) +
    _numberOfReservedTokensOutstandingFor(_nft, _i, _storedTier);
  unchecked {
    ++_i;
  }
}
function recordMintReservesFor(uint256 _tierId, uint256 _count)
  external
  override
  returns (uint256[] memory tokenIds)
{
  // Get a reference to the tier.
  JBStored721Tier storage _storedTier = _storedTierOf[msg.sender][_tierId];
  // Get a reference to the number of reserved tokens mintable for the tier.
  uint256 _numberOfReservedTokensOutstanding = _numberOfReservedTokensOutstandingFor(
    msg.sender,
    _tierId,
    _storedTier
  );
  ...
_numberOfReservedTokensOutstandingFor(_nft, _i+1, _storedTier);
