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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 render_link(self, template_pack=TEMPLATE_PACK, **kwargs):
 """ Render the link for the tab-pane. It must be called after render so css_class is updated with active if needed. """

        link_template = self.link_template % template_pack
        return render_to_string(link_template, {'link': self})