private static void findDocumentTypesWithActionableIndexingModeChange(
            List<ConfigChangeAction> actions, ContentCluster nextCluster,
            Set<String> currentTypes, Set<String> nextTypes, String currentIndexMode, String nextIndexingMode) {
        for (String type : nextTypes) {
            if (currentTypes.contains(type)) {
                List<ServiceInfo> services = nextCluster.getSearch().getSearchNodes().stream()
                        .map(SearchNode::getServiceInfo)
                        .toList();
                actions.add(VespaReindexAction.of(
                        nextCluster.id(),
                        ValidationId.indexModeChange,
                        String.format(
                                "Document type '%s' in cluster '%s' changed indexing mode from '%s' to '%s'",
                                type, nextCluster.getName(), currentIndexMode, nextIndexingMode),
                        services,
                        type
                ));
            }
        }
    }
Returns any change to the indexing mode of a cluster.

@author hmusum
@author bjorncs
config-model/src/main/java/com/yahoo/vespa/model/application/validation/change/IndexingModeChangeValidator.java