function addUpdateGrantee(address _grantee, uint256 _value) external onlyOwner onlyWhileSale{
        require(_grantee != address(0));
        require(_value > 0);

        
        if (presaleGranteesMap[_grantee] == 0) {
            require(presaleGranteesMapKeys.length < MAX_TOKEN_GRANTEES);
            presaleGranteesMapKeys.push(_grantee);
            GrantAdded(_grantee, _value);
        }
        else {
            GrantUpdated(_grantee, presaleGranteesMap[_grantee], _value);
        }

        presaleGranteesMap[_grantee] = _value;
    }