code: func (f *Function) loadConfig(environment string) error {
  	path := fmt.Sprintf("function.%s.json", environment)
  
  	ok, err := f.tryConfig(path)
  	if err != nil {
  		return err
  	}
  
  	if ok {
  		f.Log.WithField("config", path).Debug("loaded config")
  		return nil
  	}
  
  	ok, err = f.tryConfig("function.json")
  	if err != nil {
  		return err
  	}
  
  	if ok {
  		f.Log.WithField("config", "function.json").Debug("loaded config")
  		return nil
  	}
  
  	return nil
  }
docs: // loadConfig for `environment`, attempt function.ENV.js first, then
  // fall back on function.json if it is available.