func (h *Hoverfly) addAuthIfNeeded(sling *sling.Sling) (*sling.Sling, error) { if len(h.Username) > 0 || len(h.Password) > 0 && len(h.authToken) == 0 { var err error h.authToken, err = h.generateAuthToken() if err != nil { return nil, err } } if len(h.authToken) > 0 { sling.Add("Authorization", h.buildAuthorizationHeaderValue()) } return sling, nil }