    function _burn(address addressToBurn, uint256 value) private returns (bool success) {
        require(value > 0, "Tokens to burn must be greater than zero");
        require(balances[addressToBurn] >= value, "Tokens to burn exceeds balance");
        balances[addressToBurn] = balances[addressToBurn].sub(value);
        totalSupply_ = totalSupply_.sub(value);
        emit Burn(msg.sender, value);
        return true;
    }