code: func validateConfig(cfg *bzzapi.Config) (err error) {
  	for _, ensAPI := range cfg.EnsAPIs {
  		if ensAPI != "" {
  			if err := validateEnsAPIs(ensAPI); err != nil {
  				return fmt.Errorf("invalid format [tld:][contract-addr@]url for ENS API endpoint configuration %q: %v", ensAPI, err)
  			}
  		}
  	}
  	return nil
  }
docs: //validate configuration parameters