code: func newFakeFlagSet(fs *pflag.FlagSet) *pflag.FlagSet {
  	ret := pflag.NewFlagSet("", pflag.ExitOnError)
  	ret.SetNormalizeFunc(fs.GetNormalizeFunc())
  	fs.VisitAll(func(f *pflag.Flag) {
  		ret.VarP(cliflag.NoOp{}, f.Name, f.Shorthand, f.Usage)
  	})
  	return ret
  }
docs: // newFakeFlagSet constructs a pflag.FlagSet with the same flags as fs, but where
  // all values have noop Set implementations