contract Claimable {
    address private _pendingOwner;
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev The Ownable constructor sets the original `owner` of the contract to the sender
     * account.
     */
    constructor () internal {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    /**
     * @return the address of the owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

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

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

    /**
     * @return true if `msg.sender` is the owner of the contract.
     */
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    /**
     * @dev Allows the current owner to relinquish control of the contract.
     * It will not be possible to call the functions with the `onlyOwner`
     * modifier anymore.
     * @notice Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
    * @dev Allows the current owner to set the pendingOwner address.
    * @param newOwner The address to transfer ownership to.
    */
    function transferOwnership(address newOwner) onlyOwner public {
      _pendingOwner = newOwner;
    }

    /**
    * @dev Allows the pendingOwner address to finalize the transfer.
    */
    function claimOwnership() onlyPendingOwner public {
      emit OwnershipTransferred(_owner, _pendingOwner);
      _owner = _pendingOwner;
      _pendingOwner = address(0);
    }
}
/**
 * @title Claimable
 * @dev Extension for the Ownable contract, where the ownership needs to be claimed.
 * This allows the new owner to accept the transfer.
 */
function owner() public view returns (address) {
        return _owner;
    }
/**
 * @return the address of the owner.
 */