contract Ownable {
  address public owner;
 
    function Ownable () public {
        owner = msg.sender;
    }
 
    modifier onlyOwner {
        require (msg.sender == owner, "OnlyOwner methods called by non-owner.");
        _;
    }
 
    /**
     * @param  newOwner address 
     */
    function transferOwnership(address newOwner) onlyOwner public {
        if (newOwner != address(0)) {
        owner = newOwner;
      }
    }
  
}
function transferOwnership(address newOwner) onlyOwner public {
    if (newOwner != address(0)) {
    owner = newOwner;
  }
}

/**
 * @param  newOwner address 
 */