private async Task <(HttpStatusCode status, string content)> PostDocAsync(Document document)
        {
            var jsonContent = JsonConvert.SerializeObject(document);

            using (var client = TestServerHelper.CreateClient())
                using (var response = await client.PostAsync("api/docs", new StringContent(jsonContent, Encoding.UTF8, "application/json")))
                {
                    return(response.StatusCode, await response.Content.ReadAsStringAsync());
                }
        }