def order(self, order='asc'):
        """
        This method retrieve an iterable object that implements the method
        __iter__. The arguments given will compose the parameters in the
        request url.

        This method can be used compounded with query, filter,
        sort and facet methods.

        kwargs: valid SORT_VALUES arguments.

        return: iterable object of Works metadata

        Example 1:
            >>> from crossref.restful import Works
            >>> works.query('zika').sort('deposited').order('asc').url
            'https://api.crossref.org/works?sort=deposited&query=zika&order=asc'
            >>> query = works.query('zika').sort('deposited').order('asc')
            >>> for item in query:
            ...    print(item['title'], item['deposited']['date-time'])
            ...
            ['A Facile Preparation of 1-(6-Hydroxyindol-1-yl)-2,2-dimethylpropan-1-one'] 2007-02-13T20:56:13Z
            ['Contributions to the Flora of the Lake Champlain Valley, New York and Vermont, III'] 2007-02-13T20:56:13Z
            ['Pilularia americana A. Braun in Klamath County, Oregon'] 2007-02-13T20:56:13Z
            ...

        Example 2:
            >>> from crossref.restful import Works
            >>> works.query('zika').sort('deposited').order('desc').url
            'https://api.crossref.org/works?sort=deposited&query=zika&order=desc'
            >>> query = works.query('zika').sort('deposited').order('desc')
            >>> for item in query:
            ...    print(item['title'], item['deposited']['date-time'])
            ...
            ["Planning for the unexpected: Ebola virus, Zika virus, what's next?"] 2017-05-29T12:55:53Z
            ['Sensitivity of RT-PCR method in samples shown to be positive for Zika virus by RT-qPCR in vector competence studies'] 2017-05-29T12:53:54Z
            ['Re-evaluation of routine dengue virus serology in travelers in the era of Zika virus emergence'] 2017-05-29T10:46:11Z
            ...
        """

        context = str(self.context)
        request_url = build_url_endpoint(self.ENDPOINT, context)
        request_params = dict(self.request_params)

        if order not in self.ORDER_VALUES:
            raise UrlSyntaxError(
                'Sort order specified as %s but must be one of: %s' % (
                    str(order),
                    ', '.join(self.ORDER_VALUES)
                )
            )

        request_params['order'] = order

        return self.__class__(request_url, request_params, context, self.etiquette)