code: func (s *Action) GitCredentialBefore(ctx context.Context, c *cli.Context) error {
  	err := s.Initialized(ctx, c)
  	if err != nil {
  		return err
  	}
  	if !ctxutil.IsStdin(ctx) {
  		return ExitError(ctx, ExitUsage, nil, "missing stdin from git")
  	}
  	return nil
  }
docs: // GitCredentialBefore is executed before another git-credential command