var users []User
result := restclient.Get(serverUrl + "/user").
            AddQueryParam("limit", 1).
            AddQueryParam("email", "example@gmail.com").
            SendAndGetJsonResponse(&users)
            
// check internal rest client error 
if result.Err != nil {
   return result.Err
}
// check response error
if result.StatusCode != 200 {
   return errors.New(result.ResponseError)
}

// or check both at once
if err := result.Error(); err != nil {
    return err
}

var users []User
result := restclient.Get(serverUrl + "/user" + rcquery.New().Add("limit", 1).Get()).
            SendAndGetJsonResponse(&users)
if err := result.Error(); err != nil {
    return err
}

var user User{/* init */}
result := restclient.Post(serverUrl + "/user").
            AddJsonBody(user).
            Send()
if err := result.Error(); err != nil {
    return err
}