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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 create_todo_item(self, list_id, content, party_id=None, notify=False):
 """ This call lets you add an item to an existing list. The item is added to the bottom of the list. If a person is responsible for the item, give their id as the party_id value. If a company is responsible, prefix their company id with a 'c' and use that as the party_id value. If the item has a person as the responsible party, you can use the notify key to indicate whether an email should be sent to that person to tell them about the assignment. """

        path = '/todos/create_item/%u' % list_id
        req = ET.Element('request')
        ET.SubElement(req, '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)