contract Ownable {
    address public owner;

    // @dev The Ownable constructor sets the original `owner` of the contract to the sender account.
    constructor() public {
        owner = msg.sender;
    }

    // @dev Throws if called by any account other than the owner.
    modifier onlyOwner() {
        require(msg.sender == 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));
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }
}
// @title Ownable
// @dev The Ownable contract has an owner address, and provides basic authorization control
// functions, this simplifies the implementation of "user permissions".
function transferOwnership(address newOwner) public onlyOwner {
        require(newOwner != address(0));
        if (newOwner != address(0)) {
            owner = newOwner;
        }
    }
// @dev Allows the current owner to transfer control of the contract to a newOwner.
// @param newOwner The address to transfer ownership to.