contract Claimable is Ownable {
    address public pendingOwner;

    /// @dev Modifier throws if called by any account other than the pendingOwner.
    modifier onlyPendingOwner() {
        require(msg.sender == pendingOwner, "UNAUTHORIZED");
        _;
    }

    /// @dev Allows the current owner to set the pendingOwner address.
    /// @param newOwner The address to transfer ownership to.
    function transferOwnership(
        address newOwner
        )
        public
        onlyOwner
    {
        require(newOwner != address(0x0) && newOwner != owner, "INVALID_ADDRESS");
        pendingOwner = newOwner;
    }

    /// @dev Allows the pendingOwner address to finalize the transfer.
    function claimOwnership()
        public
        onlyPendingOwner
    {
        emit OwnershipTransferred(owner, pendingOwner);
        owner = pendingOwner;
        pendingOwner = address(0x0);
    }
}
function transferOwnership(
    address newOwner
    )
    public
    onlyOwner
{
    require(newOwner != address(0x0) && newOwner != owner, "INVALID_ADDRESS");
    pendingOwner = newOwner;
}

/// @dev Allows the current owner to set the pendingOwner address.
/// @param newOwner The address to transfer ownership to.