code: func initVerifier(ctx context.Context, config *oidc.Config, iss string) (*oidc.IDTokenVerifier, error) {
  	provider, err := oidc.NewProvider(ctx, iss)
  	if err != nil {
  		return nil, fmt.Errorf("init verifier failed: %v", err)
  	}
  	return provider.Verifier(config), nil
  }
docs: // initVerifier creates a new ID token verifier for the given configuration and issuer URL.  On success, calls setVerifier with the
  // resulting verifier.