code: def _domain_event_migration_iteration_cb(conn, domain, iteration, opaque):
      '''
      Domain migration iteration events handler
      '''
      _salt_send_domain_event(opaque, conn, domain, opaque['event'], {
          'iteration': iteration
      }f _domain_event_migration_iteration_cb(conn, domain, iteration, opaque):
      '''
      Domain migration iteration events handler
      '''
      _salt_send_domain_event(opaque, conn, domain, opaque['event'], {
          'iteration': iteration
      })
docs: Domain migration iteration events handler