code: def run(): # pragma: no cover
      
      out_file, out_format, arguments = parse()
      user, key = arguments.pop('user', None), arguments.pop('key', None)
      if not user or not key:
          sys.stderr.write('Credentials are required to perform API calls.\n')
          sys.exit(1)
  
      api = API(user, key, https=arguments.pop('https'), verify_ssl=arguments.pop('verify_ssl'),
                rate_limit=arguments.pop('rate_limit'))
      response = getattr(api, arguments.pop('api_call'))(**arguments)
      output = str(getattr(response, out_format) if out_format != 'list' else response.as_list())
      out_file.write(output if output.endswith('\n') else output + '\n')
docs: Defines how to start the CLI for the DomainTools API