def set_message_boundaries(self, length):
        if length > len(self):
            raise IndexError('message length greater than buffer length',
                             length, len(self))
        self._msg_start = self._offset
        self._msg_length = length
        self._msg_bytes_left = length
Set the number of bytes that can be read for the next message.
dataset/ETHPy150Open rlenglet/openfaucet/src/openfaucet/buffer.py/ReceiveBuffer.set_message_boundaries