'See if our provider_id points at our current backend.
provider_id is instanceId. The instanceId contains the ssn of the
StorageCenter it is hosted on. This must equal our current ssn or
it isn\'t valid.
:param provider_id: Provider_id from an volume or snapshot object.
:returns: True/False'

def _use_provider_id(self, provider_id):

    ret = False
    if provider_id:
        try:
            if (provider_id.split('.')[0] == six.text_type(self.ssn)):
                ret = True
            else:
                LOG.debug('_use_provider_id:    provider_id    %(pid)r    not    valid    on    %(ssn)r', {'pid': provider_id, 'ssn': self.ssn})
        except Exception:
            LOG.error('_use_provider_id:    provider_id    %s    is    invalid!', provider_id)
    return ret
