return nil
	}
	names, ok := c[claimNamesKey]
	if !ok {
		// No _claim_names, no keys to look up.
		return nil
	}

	claimToSource := map[string]string{}
	if err := json.Unmarshal([]byte(names), &claimToSource); err != nil {
		return fmt.Errorf("oidc: error parsing distributed claim names: %v", err)
	}

	rawSources, ok := c[claimSourcesKey]
	if !ok {