private static IRestRequest CreateBackendCountRequest(string municipalityName)
        {
            var filter = new PostalInformationFilter
            {
                MunicipalityName = municipalityName
            };

            return(new RestRequest("postcodes/totaal-aantal")
                   .AddFiltering(filter));
        }
        private static IRestRequest CreateBackendListRequest(
            int?offset,
            int?limit,
            Taal language,
            string sort,
            string municipalityName)
        {
            var filter = new PostalInformationFilter
            {
                MunicipalityName = municipalityName
            };

            // postcode
            var sortMapping = new Dictionary <string, string>
            {
                { "PostCode", "PostalCode" },
            };

            return(new RestRequest("postcodes?taal={language}")
                   .AddParameter("language", language, ParameterType.UrlSegment)
                   .AddPagination(offset, limit)
                   .AddFiltering(filter)
                   .AddSorting(sort, sortMapping));
        }