code: func checkFlags(c *cli.Context, flags ...string) error {
  	for _, flag := range flags {
  		if c.String(flag) == "" {
  			cli.ShowSubcommandHelp(c)
  			err := errors.Errorf("error: the required flag %q was empty or not provided", flag)
  			fmt.Fprintln(os.Stderr, err)
  			return err
  		}
  	}
  
  	return nil
  }
docs: // Utility function to check if CLI flags were given.