code: func (api *API) ListSSL(zoneID string) ([]ZoneCustomSSL, error) {
  	uri := "/zones/" + zoneID + "/custom_certificates"
  	res, err := api.makeRequest("GET", uri, nil)
  	if err != nil {
  		return nil, errors.Wrap(err, errMakeRequestError)
  	}
  	var r zoneCustomSSLsResponse
  	if err := json.Unmarshal(res, &r); err != nil {
  		return nil, errors.Wrap(err, errUnmarshalError)
  	}
  	return r.Result, nil
  }
docs: // ListSSL lists the custom certificates for the given zone.
  //
  // API reference: https://api.cloudflare.com/#custom-ssl-for-a-zone-list-ssl-configurations