contract Ownable is EternalStorage {
    /**
    * @dev Event to show ownership has been transferred
    * @param previousOwner representing the address of the previous owner
    * @param newOwner representing the address of the new owner
    */
    event OwnershipTransferred(address previousOwner, address newOwner);

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

    /**
    * @dev Tells the address of the owner
    * @return the address of the owner
    */
    function owner() public view returns (address) {
        return addressStorage[keccak256("owner")];
    }

    /**
    * @dev Allows the current owner to transfer control of the contract to a newOwner.
    * @param newOwner the address to transfer ownership to.
    */
    function transferOwnership(address newOwner) public onlyOwner {
        require(newOwner != address(0));
        setOwner(newOwner);
    }

    /**
    * @dev Sets a new owner address
    */
    function setOwner(address newOwner) internal {
        emit OwnershipTransferred(owner(), newOwner);
        addressStorage[keccak256("owner")] = newOwner;
    }
}
/**
 * @title Ownable
 * @dev This contract has an owner address providing basic authorization control
 */
function owner() public view returns (address) {
    return addressStorage[keccak256("owner")];
}

/**
 * @dev Tells the address of the owner
 * @return the address of the owner
 */