public static async Task <ProductFamily> SingleAsync(this ProductFamilyService service, string handle)
        {
            string url = string.Format(format: "/{0}/handle/{1}", arg0: ProductFamilyService.ProductFamilyKey, arg1: handle);

            return(await service.GetRequestAsync <ProductFamily>(url));
        }
        public static async Task <IEnumerable <ProductFamily> > AllAsync(this ProductFamilyService service, int familyId)
        {
            string url = string.Format(format: "/{0}/{1}/{2}", arg0: ProductFamilyService.ProductFamilyKey, arg1: familyId, arg2: ProductService.ProductKey);

            return(await service.GetRequestAsync <List <ProductFamily> >(url));
        }