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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def follow_link(self, link, **kwargs):
 """Click a link. :param Tag link: Link to click :param kwargs: Keyword arguments to `Session::send` """

        try:
            href = link['href']
        except KeyError:
            raise exceptions.RoboError('Link element must have "href" '
                                       'attribute')
        self.open(self._build_url(href), **kwargs)