generateUserDelegationSasStringToSign(options, userDelegationKey) {
        return generateBlobSASQueryParametersInternal(Object.assign({ containerName: this._containerName, blobName: this._name, snapshotTime: this._snapshot, versionId: this._versionId }, options), userDelegationKey, this.accountName).stringToSign;
    }
Only available for BlobClient constructed with a shared key credential.

Generates string to sign for a Blob Service Shared Access Signature (SAS) URI based on
the client properties and parameters passed in. The SAS is signed by the input user delegation key.

@see https://learn.microsoft.com/en-us/rest/api/storageservices/constructing-a-service-sas

@param options - Optional parameters.
@param userDelegationKey -  Return value of `blobServiceClient.getUserDelegationKey()`
@returns The SAS URI consisting of the URI to the resource represented by this client, followed by the generated SAS token.