ed with a comma.

    Override L{stringReceived} to handle received netstrings. This
    method is called with the netstring payload as a single argument
    whenever a complete netstring is received.

    Security features:
        1. Messages are limited in size, useful if you don't want
           someone sending you a 500MB netstring (change C{self.MAX_LENGTH}
           to the maximum length you wish to accept).
        2. The connection is lost if an illegal message is received.

    @ivar MAX_LENGTH: Defines the maximum length of netstrings that can be
        received.
    @type MAX_LENGTH: C{int}

    @ivar _LENGTH: A pattern describing all strings that contain a netstring
        length specification. Examples for length specifications are C{b'0:'},
        C{b'12:'}, and C{b'179:'}. C{b'007:'} is not a valid length
        specification, since leading zeros are not allowed.
    @type _LENGTH: C{re.Match}

    @ivar _LENGTH_PREFIX: A pattern describing all strings that contain
        the first part of a netstring length specification (without the
        trailing comma). Examples are '0', '12', and '179'. '007' does not
        start a netstring length specification, since leading zeros are
        not allowed.
    @type _LENGTH_PREFIX: C{re.Match}

    @ivar _PARSING_LENGTH: Indicates that the C{NetstringReceiver} is in
        the state of parsing the length portion of a netstring.
    @type _PARSING_LENGTH: C{int}

    @ivar _PARSING_PAYLOAD: Indicates that the C{NetstringReceiver} is in
        the state of parsing the payload portion (data and trailing comma)
        of a netstring.
    @type _PARSING_PAYLOAD: C{int}

    @ivar brokenPeer: Indicates if the connection is still functional
    @type brokenPeer: C{int}

    @ivar _state: Indicates if the protocol is consuming the length portion
        (C{PARSING_LENGTH}) or the payload (C{PARSING_PAYLOAD}) of a netstring
    @type _state: C{int}

    @ivar _remainingData: Holds the chunk of data that has not yet been consumed
    @type _remainingData: C{string}

    @ivar _payload: Holds the payload portion of a netstring including the
        trailing comma
    @type _payload: C{BytesIO}

    @ivar _expectedPayloadSize: Holds the payload size plus one for the trailing
        comma.
    @type _expectedPayloadSize: C{int}
    韆