contract Ownable {
  
  address public owner;
  address public newOwner;

  event OwnershipTransferred(address _from, address _to);
  
  /**
   * @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() {
    assert(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 {
    assert(_newOwner != address(0));      
    newOwner = _newOwner;
  }

  /**
   * @dev Accept transferOwnership.
   */
  function acceptOwnership() public {
    if (msg.sender == newOwner) {
      emit OwnershipTransferred(owner, newOwner);
      owner = newOwner;
    }
  }
}
/**
 * @title Ownable contract - base contract with an owner
 */
function transferOwnership(address _newOwner) public onlyOwner {
    assert(_newOwner != address(0));      
    newOwner = _newOwner;
  }
/**
 * @dev Allows the current owner to transfer control of the contract to a newOwner.
 * @param _newOwner The address to transfer ownership to.
 */