'Check whether initiator iqn exists.'

def verify_initiator(self, iqn):

    svc = ('/api/san/v1/iscsi/initiators/' + iqn)
    ret = self.rclient.get(svc)
    if (ret.status != restclient.Status.OK):
        exception_msg = (_('Error    Verifying    Initiator:    %(iqn)s    Return    code:    %(ret.status)d    Message:    %(ret.data)s.') % {'initiator': iqn, 'ret.status': ret.status, 'ret.data': ret.data})
        LOG.error(exception_msg)
        raise exception.VolumeBackendAPIException(data=exception_msg)
