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
import org.elasticsearch.health.HealthIndicatorResult;
import org.elasticsearch.health.HealthStatus;
import org.elasticsearch.health.SimpleHealthIndicatorDetails;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.test.ESTestCase;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import static java.util.stream.Collectors.toMap;
import static org.elasticsearch.cluster.metadata.SingleNodeShutdownMetadata.Type.RESTART;
import static org.elasticsearch.cluster.routing.ShardRouting.newUnassigned;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorService.NAME;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorServiceTests.ShardState.AVAILABLE;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorServiceTests.ShardState.INITIALIZING;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorServiceTests.ShardState.RESTARTING;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorServiceTests.ShardState.UNAVAILABLE;
import static org.elasticsearch.common.util.CollectionUtils.concatLists;
import static org.elasticsearch.core.TimeValue.timeValueSeconds;
import static org.elasticsearch.health.HealthStatus.GREEN;
import static org.elasticsearch.health.HealthStatus.RED;
import static org.elasticsearch.health.HealthStatus.YELLOW;
import static org.elasticsearch.health.ServerHealthComponents.DATA;
import static org.hamcrest.Matchers.equalTo;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
public class ShardsAvailabilityHealthIndicatorServiceTests extends ESTestCase {