Fetch document located at ``url`` and save to to ``location``.

def download(self, url, location, **kwargs):
        """
        Fetch document located at ``url`` and save to to ``location``.
        """

        doc = self.go(url, **kwargs)
        with open(location, 'wb') as out:
            out.write(doc.body)
        return len(doc.body)