pragma solidity 0.4.20;


import 'libraries/IOwnable.sol';


/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable is IOwnable {
    address internal owner;

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

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

    function getOwner() public view returns (address) {
        return 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 returns (bool) {
        if (_newOwner != address(0)) {
            onTransferOwnership(owner, _newOwner);
            owner = _newOwner;
        }
        return true;
    }

    // Subclasses of this token may want to send additional logs through the centralized Augur log emitter contract
    function onTransferOwnership(address, address) internal returns (bool);
}