public static void UploadEmptyPage(this IStoragePageBlob blob)
        {
            if (blob == null)
            {
                throw new ArgumentNullException("blob");
            }

            using (CloudBlobStream stream = blob.OpenWriteAsync(512, CancellationToken.None).GetAwaiter().GetResult())
            {
                stream.CommitAsync().Wait();
            }
        }
        public CloudPageBlob Convert(IStorageBlob input)
        {
            if (input == null)
            {
                return(null);
            }

            IStoragePageBlob pageBlob = input as IStoragePageBlob;

            if (pageBlob == null)
            {
                throw new InvalidOperationException("The blob is not a page blob.");
            }

            return(pageBlob.SdkObject);
        }