public IEnumerator FulfillUserItem(string @namespace, string userId, string accessToken, FulfillmentRequest fulfillmentRequest, ResultCallback <FulfillmentResult> callback) { Assert.IsNotNull(@namespace, $"{nameof(@namespace)} cannot be null"); Assert.IsNotNull(userId, $"{nameof(userId)} cannot be null"); Assert.IsNotNull(accessToken, $"{nameof(accessToken)} cannot be null"); Assert.IsNotNull(fulfillmentRequest, $"{nameof(fulfillmentRequest)} cannot be null"); var request = HttpRequestBuilder .CreatePost(this.baseUrl + "/admin/namespaces/{namespace}/users/{userId}/fulfillment") .WithPathParam("namespace", @namespace) .WithPathParam("userId", userId) .WithBearerAuth(accessToken) .WithContentType(MediaType.ApplicationJson) .Accepts(MediaType.ApplicationJson) .WithBody(fulfillmentRequest.ToUtf8Json()) .GetResult(); IHttpResponse response = null; yield return(this.httpClient.SendRequest(request, rsp => response = rsp)); var result = response.TryParseJson <FulfillmentResult>(); callback.Try(result); }