private void pingIterationCompletedSingleGroup(SearchGroupsImpl groups) {
        Group group = groups.groups().iterator().next();
        group.aggregateNodeValues();
        // With just one group sufficient coverage may not be the same as full coverage, as the
        // group will always be marked sufficient for use.
        updateSufficientCoverage(group, true);
        boolean sufficientCoverage = groups.isGroupCoverageSufficient(group.hasSufficientCoverage(),
                                                                      group.activeDocuments(), group.activeDocuments(), group.activeDocuments());
        trackGroupCoverageChanges(group, sufficientCoverage, group.activeDocuments(), group.activeDocuments());
    }
Used by the cluster monitor to manage node status
container-search/src/main/java/com/yahoo/search/dispatch/searchcluster/SearchCluster.java