function reclaimExpiredOptionTokens(address[] beneficiaries) public onlyOwner returns (uint reclaimedTokenAmount) {
        reclaimedTokenAmount = 0;
        for (uint i=0; i<beneficiaries.length; i++) {
            Option storage option = grantedOptions[beneficiaries[i]];
            if (option.expiration <= block.timestamp) {
                reclaimedTokenAmount = reclaimedTokenAmount.add(option.tokenAmount);
                option.tokenAmount = 0;

                emit ReclaimOption(beneficiaries[i]);
            }
        }
        issuedTokens = issuedTokens.sub(reclaimedTokenAmount);
        require(ERC20(token).transfer(owner, reclaimedTokenAmount));
    }