No GetBlobReferenceFromServerAsync method

[dtretyakov]

        /// <summary>
        ///     Requests that the service start to copy a blob's contents, properties, and metadata to a new blob asynchronously.
        /// </summary>
        /// <param name="blobClient">Cloud blob client.</param>
        /// <param name="source">The URI of a source blob.</param>
        /// <param name="sourceAccessCondition">An object that represents the access conditions for the source blob.</param>
        /// <param name="destAccessCondition">An object that represents the access conditions for the destination blob.</param>
        /// <param name="cancellationToken">Cancellation token.</param>
        /// <returns>
        ///     The copy ID associated with the copy operation.
        /// </returns>
        public static Task<string> GetBlobReferenceFromServerAsync(
            ICloudBlob blobClient,
            Uri source,
            AccessCondition sourceAccessCondition = null,
            AccessCondition destAccessCondition = null,
            CancellationToken cancellationToken = default (CancellationToken))
        {
            ICancellableAsyncResult asyncResult = blobClient.BeginStartCopyFromBlob(source, sourceAccessCondition, destAccessCondition, null, null, null, null);
            CancellationTokenRegistration registration = cancellationToken.Register(p => asyncResult.Cancel(), null);

            return Task<string>.Factory.FromAsync(
                asyncResult,
                result =>
                    {
                        registration.Dispose();
                        return blobClient.EndStartCopyFromBlob(result);
                    });
        }

[dtretyakov]

Not required.