'Get the storage driver the acceptance testing nodes will use.
:return: A ``BackendDescription`` matching the name of the backend
chosen by the command-line options.'

def dataset_backend(self):

    configuration = self.dataset_backend_configuration()
    dataset_backend_name = configuration.get('backend', self['dataset-backend'])
    try:
        return backend_loader.get(dataset_backend_name)
    except ValueError:
        raise UsageError('Unknown    dataset    backend:    {}'.format(dataset_backend_name))
