code: def validate(self,options):
          
          if not options.port:
              self.parser.error("'port' is required")
          if options.port == options.monitor_port:
              self.parser.error("'port' and 'monitor-port' must not be the same.")
          if options.buffer_size <= 0:
              self.parser.error("'buffer_size' must be > 0.")
          try:
              codecs.getencoder(options.char_encoding)
          except LookupError:
              self.parser.error("invalid 'char-encoding' %s" % options.char_encoding)
  
          if not options.host:
             options.host = socket.gethostname()
docs: Validate the options or exit()