public Curator.DirectoryCache createApplicationsPathCache(ExecutorService zkCacheExecutor) {
        return curator.createDirectoryCache(applicationsPath.getAbsolute(), false, false, zkCacheExecutor);
    }
Sets up a listenable cache with the given listener, over the applications path of this tenant.
configserver/src/main/java/com/yahoo/vespa/config/server/application/ApplicationCuratorDatabase.java