code:     protected Settings nodeSettings(int nodeOrdinal) {
          return ImmutableSettings.builder()
                  // we really need local GW here since this also checks for corruption etc.
                  // and we need to make sure primaries are not just trashed if we don't have replicas
                  .put(super.nodeSettings(nodeOrdinal)).put("gateway.type", "local")
                  .put(TransportModule.TRANSPORT_SERVICE_TYPE_KEY, MockTransportService.class.getName())
                          // speed up recoveries
                  .put(RecoverySettings.INDICES_RECOVERY_CONCURRENT_STREAMS, 10)
                  .put(RecoverySettings.INDICES_RECOVERY_CONCURRENT_SMALL_FILE_STREAMS, 10)
                  .put(ThrottlingAllocationDecider.CLUSTER_ROUTING_ALLOCATION_NODE_CONCURRENT_RECOVERIES, 5)
                  .build();
      }
  
      /**
       * Tests that we can actually recover from a corruption on the primary given that we have replica shards around.
       */
      @Test
  