Find a better way for specifying return fields

[johanv]

You can request specific the CiviCRM api to return specific fields, e.g. like this:

        var apiResult = ServiceHelper.CallService<ICiviCrmApi, ApiResultValues<Event>>(
            svc =>
                svc.EventGet(_apiKey, _siteKey,
                    new EventRequest {GapUitstapId = bivak.UitstapID, ReturnFields = "id,title,start_date"}));

But this is error prone, especially when using custom fields. Ideally we should be able to use lambda expressions, e.g.

ReturnFields = (l => new { l.Id, l.Title, l.StartDate })