* <code>shareddatalayer::Error::BACKEND_FAILURE</code>:<br>
* shareddatalayer delivered the request to the backend data storage but the backend data storage failed to process the request.
* In case of a write type request, data in the backend data storage may or may not have been altered.<br>
* <code>shareddatalayer::Error::BACKEND_FAILURE</code>:<br>
* shareddatalayer delivered the request to the backend data storage but the backend data storage failed to process the request.
* In case of a write type request, data in the backend data storage may or may not have been altered.<br>