PropertyBagConsumer.cs

public class MyCoolService
{
    public Result<CoolThing> Fetch(Uri uri)
    {
        HttpResponseMessage response = CallThatThingInTheCloud(uri);

        if (response.IsSuccessStatusCode)
        {
            return new Result<CoolThing>
                {
                    IsSuccess = true,
                    Results = Deserialize(response)
                };
        }

        return new Result<CoolThing>
            {
                IsSuccess = false,
                ErrorMessage = string.Format("Error {0}: {1}", 
                                response.StatusCode, response.ReasonPhrase)
            };
    }
    //...
}