How to use the pyrad.packet.PacketError function in pyrad

dict=self.server.dict,
                                packet=data)
                if self.server.enable_pkt_verify:
                    if req.VerifyCoARequest():
                        raise PacketError('Packet verification failed')

            elif self.server_type == ServerType.Acct:

                if req.code != AccountingRequest:
                    raise ServerPacketError('Received non-acct packet on acct port')
                req = AcctPacket(secret=remote_host.secret,
                                 dict=self.server.dict,
                                 packet=data)
                if self.server.enable_pkt_verify:
                    if req.VerifyAcctRequest():
                        raise PacketError('Packet verification failed')

            # Call request callback
            self.request_callback(self, req, addr)
        except Exception as exc:
            if self.server.debug:
                self.logger.exception('[%s:%d] Error for packet from %s', self.ip, self.port, addr)
            else:
                self.logger.error('[%s:%d] Error for packet from %s: %s', self.ip, self.port, addr, exc)

        process_date = datetime.utcnow()
        self.logger.debug('[%s:%d] Request from %s processed in %d ms', self.ip, self.port, addr, (process_date-receive_date).microseconds/1000)

def datagramReceived(self, datagram, source):
        host, port = source
        try:
            pkt = self.CreatePacket(packet=datagram)
        except packet.PacketError as err:
            log.msg('Dropping invalid packet: ' + str(err))
            return

        if host not in self.hosts:
            log.msg('Dropping packet from unknown host ' + host)
            return

        pkt.source = (host, port)
        try:
            self.processPacket(pkt)
        except PacketError as err:
            log.msg('Dropping packet from %s: %s' % (host, str(err)))

except struct.error:
            raise PacketError('Packet header is corrupt')
        if len(packet) != length:
            raise PacketError('Packet has invalid length')
        if length > 8192:
            raise PacketError('Packet length is too long (%d)' % length)

        self.clear()

        packet = packet[20:]
        while packet:
            try:
                (key, attrlen) = struct.unpack('!BB', packet[0:2])
            except struct.error:
                raise PacketError('Attribute header is corrupt')

            if attrlen < 2:
                raise PacketError(
                        'Attribute length is too small (%d)' % attrlen)

            value = packet[2:attrlen]
            if key == 26:
                for (key, value) in self._PktDecodeVendorAttribute(value):
                    self.setdefault(key, []).append(value)
            elif key == 80:
                # POST: Message Authenticator AVP is present.
                self.message_authenticator = True
                self.setdefault(key, []).append(value)

            elif self.dict.attributes[self._DecodeKey(key)].type == 'tlv':
                self._PktDecodeTlvAttribute(key,value)

def DecodePacket(self, packet):
        """Initialize the object from raw packet data.  Decode a packet as
        received from the network and decode it.

        :param packet: raw packet
        :type packet:  string"""

        try:
            (self.code, self.id, length, self.authenticator) = \
                    struct.unpack('!BBH16s', packet[0:20])

        except struct.error:
            raise PacketError('Packet header is corrupt')
        if len(packet) != length:
            raise PacketError('Packet has invalid length')
        if length > 8192:
            raise PacketError('Packet length is too long (%d)' % length)

        self.clear()

        packet = packet[20:]
        while packet:
            try:
                (key, attrlen) = struct.unpack('!BB', packet[0:2])
            except struct.error:
                raise PacketError('Attribute header is corrupt')

            if attrlen < 2:
                raise PacketError(

def DecodePacket(self, packet):
        """Initialize the object from raw packet data.  Decode a packet as
        received from the network and decode it.

        :param packet: raw packet
        :type packet:  string"""

        try:
            (self.code, self.id, length, self.authenticator) = \
                    struct.unpack('!BBH16s', packet[0:20])

        except struct.error:
            raise PacketError('Packet header is corrupt')
        if len(packet) != length:
            raise PacketError('Packet has invalid length')
        if length > 8192:
            raise PacketError('Packet length is too long (%d)' % length)

        self.clear()

        packet = packet[20:]
        while packet:
            try:
                (key, attrlen) = struct.unpack('!BB', packet[0:2])
            except struct.error:
                raise PacketError('Attribute header is corrupt')

            if attrlen < 2:
                raise PacketError(
                        'Attribute length is too small (%d)' % attrlen)

def datagramReceived(self, datagram, (host, port)):
        try:
            pkt = self.CreatePacket(packet=datagram)
        except packet.PacketError as err:
            log.msg('Dropping invalid packet: ' + str(err))
            return

        if host not in self.hosts:
            log.msg('Dropping packet from unknown host ' + host)
            return

        pkt.source = (host, port)
        try:
            self.processPacket(pkt)
        except PacketError as err:
            log.msg('Dropping packet from %s: %s' % (host, str(err)))

if len(packet) != length:
            raise PacketError('Packet has invalid length')
        if length > 8192:
            raise PacketError('Packet length is too long (%d)' % length)

        self.clear()

        packet = packet[20:]
        while packet:
            try:
                (key, attrlen) = struct.unpack('!BB', packet[0:2])
            except struct.error:
                raise PacketError('Attribute header is corrupt')

            if attrlen < 2:
                raise PacketError(
                        'Attribute length is too small (%d)' % attrlen)

            value = packet[2:attrlen]
            if key == 26:
                for (key, value) in self._PktDecodeVendorAttribute(value):
                    self.setdefault(key, []).append(value)
            elif key == 80:
                # POST: Message Authenticator AVP is present.
                self.message_authenticator = True
                self.setdefault(key, []).append(value)

            elif self.dict.attributes[self._DecodeKey(key)].type == 'tlv':
                self._PktDecodeTlvAttribute(key,value)
            else:
                self.setdefault(key, []).append(value)