private AttachmentReference UploadAttachment(AzureDevOpsWorkItemAttachment attachment)
        {
            AttachmentReference uploadedFile;

            var name = Path.GetFileName(attachment.AttachmentPath);

            using (var attStream = new FileStream(attachment.AttachmentPath, FileMode.Open, FileAccess.Read))
            {
                uploadedFile = WorkItemTrackingHttpClient.CreateAttachmentAsync(attStream, ProjectName, fileName: name)
                               .Result;
            }

            return(uploadedFile);
        }
        private void UploadAttachmentToWorkItem(int workItemId, AzureDevOpsWorkItemAttachment attachment)
        {
            var uploadedFileReference = UploadAttachment(attachment);

            const string relationText = "/relations/-";
            var          patch        = new JsonPatchDocument
            {
                new JsonPatchOperation
                {
                    Operation = Operation.Add,
                    Path      = relationText,
                    Value     = new
                    {
                        rel        = "AttachedFile",
                        url        = uploadedFileReference.Url,
                        attributes = new { comment = attachment.Comment }
                    }
                }
            };

            Update(workItemId, patch);
        }