code: def check_args(args):
      
      # Checking that only VCF can have a - (stdout) as output
      if args.output_format not in _streamable_format and args.output == "-":
          logger.error("{} format cannot be streamed to standard output"
                       "".format(args.output_format))
          sys.exit(1)
  
      # Checking the file extensions
      if args.output_format == "vcf" and args.output != "-":
          if not args.output.endswith(".vcf"):
              args.output += ".vcf"
  
      elif args.output_format == "plink":
          if args.output.endswith(".bed"):
              args.output = args.output[:-4]
docs: Checks the arguments and options.