    function release (address account) public isVestedAccount(account) {
        uint256 unreleased = releasableAmount(account);
        require(unreleased > 0);
        beneficiary[account].releasedAmount = beneficiary[account].releasedAmount.add(unreleased);
        token.transfer(account, unreleased);
        emit Released(account, unreleased);
        if (beneficiary[account].releasedAmount == beneficiary[account].totalAmount) {  
            delete beneficiary[account];
        }
    }