    function _issueReward(address to_) internal {
        rewardToken.safeTransfer(to_, reward);
        emit RewardIssued(to_, reward);
    }
    /// @inheritdoc IHeart
    function withdrawUnspentRewards(ERC20 token_) external onlyRole("heart_admin") {
        token_.safeTransfer(msg.sender, token_.balanceOf(address(this)));
    }
