This will return the metadata for all of the lists in a given project.
        You can further constrain the query to only return those lists that
        are "complete" (have no uncompleted items) or "uncomplete" (have
        uncompleted items remaining).

def todo_lists(self, project_id, complete=None):
        """
        This will return the metadata for all of the lists in a given project.
        You can further constrain the query to only return those lists that
        are "complete" (have no uncompleted items) or "uncomplete" (have
        uncompleted items remaining).
        """
        path = '/projects/%u/todos/lists' % project_id
        req = ET.Element('request')
        if complete is not None:
            ET.SubElement(req, 'complete').text = str(bool(complete)).lower()
        return self._request(path, req)