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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 update_todo_item(self, item_id, content, party_id=None, notify=False):
 """ Modifies an existing item. The values work much like the "create item" operation, so you should refer to that for a more detailed explanation. """

        path = '/todos/update_item/%u' % item_id
        req = ET.Element('request')
        item = ET.Element('request')
        ET.SubElement(item, 'content').text = str(content)
        if party_id is not None:
            ET.SubElement(req, 'responsible-party').text = str(party_id)
            ET.SubElement(req, 'notify').text = str(bool(notify)).lower()
        return self._request(path, req)