code: def i2m(self, pkt, i):
          Internal" (IP as bytes, mask as int) to "machine"
          representation."""
          mask, ip = i
          ip = socket.inet_aton(ip)
          return struct.pack(">B", mask) + ip[:self.mask2iplen(mask)]
docs: Internal" (IP as bytes, mask as int) to "machine"
          representation.