def advance(self, length):
    new_position = self.__position + length
    if new_position < 0 or new_position > len(self.__data):
      raise Exception('Invalid advance amount (%s) for cursor.  '
                      'Position=%s' % (length, new_position))
    self.__position = new_position
Advance the cursor in data buffer 'length' bytes.
dataset/ETHPy150Open uwdata/termite-data-server/web2py/gluon/contrib/pymysql/connections.py/MysqlPacket.advance