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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 add_page(self, slug):
        '''
        Add new page.
        '''

        post_data = self.get_post_data()

        post_data['user_name'] = self.userinfo.user_name

        if MWiki.get_by_uid(slug):
            self.set_status(400)
            return False
        else:
            MWiki.create_page(slug, post_data)
            tornado.ioloop.IOLoop.instance().add_callback(self.cele_gen_whoosh)
            self.redirect('/page/{0}'.format(slug))