def readline(self):

        if self._read_pos >= len(self._read_data):
            return ''
        end_index = self._read_data.find('\n', self._read_pos) + 1
        if not end_index:
            end_index = len(self._read_data)
        return self._read_up_to(end_index)
Override mod_python.apache.mp_conn.readline.
dataset/ETHPy150Open google/pywebsocket/test/mock.py/MockConn.readline