code: func NewAPI(opts ...apiOption) (*API, error) {
  	api := &API{}
  
  	for _, opt := range opts {
  		err := opt(api)
  		if err != nil {
  			return nil, errors.Wrap(err, "applying option")
  		}
  	}
  	return api, nil
  }
docs: // NewAPI returns a new API instance.