code: def get_common_args(parser, args=None):
      
  
      options = parser.parse_args(args)
      # TCP Port to listen on.
      port = options.port
  
      # Network address to bind listener to
      address = options.bind_address
  
      # Unix file socket to listen on
      unix_socket = options.unix_socket
  
      # Debug level.
      log_level = options.log_level
  
      # Server key path.
      keyfile = options.key_file or KEY_FILE
  
      # Server cert path.
      certfile = options.cert_file or CERT_FILE
  
      # CA cert path.
      cafile = options.ca_file or CA_FILE
  
      common_args = dict()
      common_args['port'] = port
      common_args['address'] = address
      common_args['unix_socket'] = unix_socket
      common_args['keyfile'] = keyfile
      common_args['certfile'] = certfile
      common_args['cafile'] = cafile
      common_args['log_level'] = log_level
      common_args['foreground'] = options.foreground
      common_args['log_file'] = options.log_file
      common_args['version'] = options.version
  
      return common_args
docs: Return list of OSPD common command-line arguments from parser, after
      validating provided values or setting default ones.