def with_cursor(self, start_cursor=None, end_cursor=None):
    if start_cursor is None:
      self._cursor = None
    else:
      self._cursor = websafe_decode_cursor(start_cursor)

    if end_cursor is None:
      self._end_cursor = None
    else:
      self._end_cursor = websafe_decode_cursor(end_cursor)

    return self
Set the start and end of this query using serialized cursors.
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/db/__init__.py/_BaseQuery.with_cursor