private UpstreamInstance getClusterLastUpdateInstance(final DiscoverySyncData discoverySyncData) {
        if (!supportSwaggerPluginSet.contains(discoverySyncData.getPluginName())) {
            LOG.info("getClusterLastUpdateInstance. pluginName={} does not support pulling API documents.", discoverySyncData.getPluginName());
            return null;
        }
        List<UpstreamInstance> allInstances = getInstances2(discoverySyncData.getUpstreamDataList(), discoverySyncData.getSelectorName());
        if (Objects.isNull(allInstances)) {
            return null;
        }
        return getClusterLastUpdateInstance(allInstances);
    }
Get the last started healthy instance of each cluster.

@return List
shenyu-admin/src/main/java/org/apache/shenyu/admin/service/manager/impl/LoadServiceDocEntryImpl.java