code: def handle(self, pkt, raddress, rport):
          
          log.debug("In TftpStateServerStart.handle")
          if isinstance(pkt, TftpPacketRRQ):
              log.debug("Handling an RRQ packet")
              return TftpStateServerRecvRRQ(self.context).handle(pkt,
                                                                 raddress,
                                                                 rport)
          elif isinstance(pkt, TftpPacketWRQ):
              log.debug("Handling a WRQ packet")
              return TftpStateServerRecvWRQ(self.context).handle(pkt,
                                                                 raddress,
                                                                 rport)
          else:
              self.sendError(TftpErrors.IllegalTftpOp)
              raise TftpException("Invalid packet to begin up/download: %s" % pkt)
docs: Handle a packet we just received.