    function _createVesting(
        address _beneficiary,
        uint256 _totalAmount,
        uint256 _stepsClaimed,
        bool _isInternal
    ) internal {
        ...
        if (numOfSteps - _vestings[_beneficiary].stepsClaimed != 0) {
            // @audit release rate calculation may round down to 1 or 0
            _vestings[_beneficiary].releaseRate =
                (_vestings[_beneficiary].totalAmount - _vestings[_beneficiary].amountClaimed) /
                (numOfSteps - _vestings[_beneficiary].stepsClaimed);
        }
        ...
    }
