eg
```
"impacts": [
            {
              "severity": 3,
              "description": "Searches might return slower than usual. Fewer redundant copies of the data exist on 2 indices [.ds-logslogslogs-2022.03.29-000001, my-index-000001].",
              "impact_areas": [ "search" ]
            }
          ]
```
server/src/test/java/org/elasticsearch/cluster/routing/allocation/ShardsAvailabilityHealthIndicatorServiceTests.java
}
    public void testShouldBeGreenWhenThereAreRestartingPrimaries() {
        var clusterState = createClusterStateWith(
            List.of(index("restarting-index", new ShardAllocation("node-0", RESTARTING, System.nanoTime()))),
            List.of(new NodeShutdown("node-0", RESTART, 60))
        );
        var service = createAllocationHealthIndicatorService(clusterState);
        assertThat(
            service.calculate(true),
            equalTo(
                createExpectedResult(
                    GREEN,
                    "This cluster has 1 restarting primary.",
                    Map.of("restarting_primaries", 1),
                    Collections.emptyList()
                )
            )
        );
    }
    public void testShouldBeRedWhenRestartingPrimariesReachedAllocationDelayAndNoReplicas() {
        var clusterState = createClusterStateWith(
            List.of(
                index(
                    "restarting-index",
                    new ShardAllocation("node-0", RESTARTING, System.nanoTime() - timeValueSeconds(between(60, 120)).nanos())
                )
            ),
            List.of(new NodeShutdown("node-0", RESTART, 60))
        );
        var service = createAllocationHealthIndicatorService(clusterState);