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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 _retrieve(self):
 """Query Apache Tomcat Server Status Page in XML format and return the result as an ElementTree object. @return: ElementTree object of Status Page XML. """

        url = "%s://%s:%d/manager/status" % (self._proto, self._host, self._port)
        params = {}
        params['XML'] = 'true'
        response = util.get_url(url, self._user, self._password, params)
        tree = ElementTree.XML(response)
        return tree