contract BalancerOwnable {
    // State variables

    address private _owner;

    // Event declarations

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    // Modifiers

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == msg.sender, "ERR_NOT_CONTROLLER");
        _;
    }

    // Function declarations

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() internal {
        _owner = msg.sender;
    }

    /**
     * @notice Transfers ownership of the contract to a new account (`newOwner`).
     *         Can only be called by the current owner
     * @dev external for gas optimization
     * @param newOwner - address of new owner
     */
    function setController(address newOwner) external onlyOwner {
        require(newOwner != address(0), "ERR_ZERO_ADDRESS");

        emit OwnershipTransferred(_owner, newOwner);

        _owner = newOwner;
    }

    /**
     * @notice Returns the address of the current owner
     * @dev external for gas optimization
     * @return address - of the owner (AKA controller)
     */
    function getController() external view returns (address) {
        return _owner;
    }
}
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
function setController(address newOwner) external onlyOwner {
    require(newOwner != address(0), "ERR_ZERO_ADDRESS");

    emit OwnershipTransferred(_owner, newOwner);

    _owner = newOwner;
}

/**
 * @notice Transfers ownership of the contract to a new account (`newOwner`).
 *         Can only be called by the current owner
 * @dev external for gas optimization
 * @param newOwner - address of new owner
 */