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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 pingback_url(self, server_name, target_url):
 """ Do a pingback call for the target URL. """

        try:
            server = ServerProxy(server_name)
            reply = server.pingback.ping(self.entry_url, target_url)
        except (Error, socket.error):
            reply = '%s cannot be pinged.' % target_url
        return reply