'Attach a volume to the host.'

@proxy._trace_time
@proxy.logger
def initialize_connection(self, volume, connector, **kwargs):

    lun = Lun(volume)
    LOG.info('Attach    the    volume    %s.', lun.ds_id)
    if (lun.group and lun.failed_over):
        backend_helper = self._replication.get_target_helper()
    else:
        backend_helper = self._helper
    return backend_helper.initialize_connection(lun.ds_id, connector, **kwargs)
