public static async Task <AttachmentContent> GetAssetByNameOrThrow(this ISquidexAttachmentClient that, string application, string fileName)
        {
            var item = await that.GetAssetByNameOrDefault(application, fileName);

            if (item == null)
            {
                throw new ArgumentNullException("fileName", $"An 'Attachment' with the fileName '{fileName}' was not found on the application '{application}'");
            }

            return(item);
        }
        public static async Task <bool> AttachmentExists(this ISquidexAttachmentClient that, string application, string fileName = null)
        {
            var item = await that.GetAssetByNameOrDefault(application, fileName);

            return(item != null);
        }